High-pressure synthesis of bilayer nickelate Sr3Ni2O5Cl2 with a tetra­gonal crystal structure

Yamane, K.; Matsushita, Y.; Adachi, S.; Hiroto, T.; Matsumoto, R.; Terashima, K.; Sakurai, H.; Takano, Y.

doi:10.1107/S2053229625002281

research papers

STRUCTURAL
CHEMISTRY

ISSN: 2053-2296

Volume 81| Part 5| May 2025| Pages 259-263

https://doi.org/10.1107/S2053229625002281

High-pressure synthesis of bilayer nickelate Sr₃Ni₂O₅Cl₂ with a tetragonal crystal structure

Kazuki Yamane,^a,^b ^* Yoshitaka Matsushita,^c Shintaro Adachi,^d Takanobu Hiroto,^c Ryo Matsumoto,^a Kensei Terashima,^a Hiroya Sakurai ^a and Yoshihiko Takano ^a,^b

^aInternational Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan, ^bGraduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan, ^cResearch Network and Facility Services Division (RNFS), National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan, and ^dNagamori Institute of Actuators, Kyoto University of Advanced Science, 18 Gotanda, Yamanouchi, Ukyo 615-8577, Japan
^*Correspondence e-mail: yamane.kazuki@nims.go.jp

Edited by R. Diniz, Universidade Federal de Minas Gerais, Brazil (Received 13 December 2024; accepted 13 March 2025; online 4 April 2025)

Motivated by a theoretical prediction of its potential superconductivity under ambient pressure, a novel oxychloride, Sr₃Ni₂O₅Cl₂, was synthesized for the first time. This synthesis utilized a high pressure of 10 GPa at 1673 K. Small single crystals were used to determine the crystal structure and measure the temperature dependence of electrical resistance. The crystal is isostructural with the recently discovered superconductor La₃Ni₂O₇, in line with theoretical expectation.

Keywords: crystal structure; superconductor; perovskite; complex anion; X-ray diffraction; Ruddlesden-Popper; oxychloride; nickel; strontium.

CCDC reference: 2431174

1. Introduction

Recently, La₃Ni₂O₇ has been reported to exhibit superconductivity under pressures exceeding 15 GPa (Sun et al., 2023 ). Remarkably, the superconducting transition temperature reaches as high as 80 K, comparable to that of high-T_c cuprates. The compound adopts a Ruddlesden–Popper phase structure and the superconductivity occurs in the double layers of NiO₂ square lattices like the superconductivity in CuO₂ square lattices in the cuprates. These intriguing characteristics have motivated the search for other Ni oxide superconductors (Sakakibara et al., 2024b ; Nagata et al., 2024 ; Ueki et al., 2024 ), with the hope that one might exhibit superconductivity at ambient pressure. This would achieve a significant breakthrough in the field.

The superconductivity of La₃Ni₂O₇ had been theoretically predicted even before its experimental discovery, as the intercoupling between two square lattices in the double layer is thought to be advantageous for superconductivity (Nakata et al., 2017 ; Sakakibara et al., 2024a ; Kaneko et al., 2024 ). Thus, the key to the occurrence of superconductivity is widely believed to lie in the Ni—O_ap—Ni bridging angle (Sun et al., 2023), where O_ap represents the oxygen ion between two Ni ions along the c axis. In fact, the superconductivity appears above the pressure at which the orthorhombic Amam structure transforms into the tetragonal I4/mmm structure (Wang et al., 2024a , 2024b ). This transformation causes the bridging angle to change from 168 to 180°, presumably enhancing the intercoupling between the two square lattices.

Based on the same theoretical approach used to predict the superconductivity of La₃Ni₂O₇, the previously unreported compound Sr₃Ni₂O₅Cl₂ has recently been proposed as a promising candidate for a superconductor under ambient pressure (Ochi et al., 2025 ). It is expected to exhibit tetragonal I4/mmm symmetry even under ambient pressure, if it exists. Therefore, we decided to synthesize this new Ni oxychloride and successfully obtained a single crystal. In this article, we present the method of synthesis, crystal structure and electrical resistance measurements for Sr₃Ni₂O₅Cl₂.

2. Experimental

2.1. Methods

Single crystals were examined using a scanning electron microscope (SEM, JSM-6010LA, JEOL) equipped with energy-dispersive X-ray spectroscopy (EDX) for elemental analysis. The compositional error in the EDX measurements was determined by measuring the same location of the crystal multiple times and calculating the standard deviation from the statistical distribution. Single-crystal X-ray diffraction (SCXRD) data were collected at 300 K using a Rigaku Synergy Custom DW single-crystal diffractometer with VariMax confocal optics for Mo Kα radiation (λ = 0.71073 Å) and a HyPix2000 detector. A crystal with dimensions of approximately 30 µm × 27 µm × 19 µm was isolated under paraffin oil, then immediately mounted in a dry N₂ gas stream to prevent degradation, as the compound is highly air-sensitive. Electrical resistance measurements were performed under various pressures using a diamond anvil cell (DAC) equipped with boron-doped diamond electrodes directly fabricated onto the diamond surface (Matsumoto et al., 2016 ; Sakakibara et al., 2024b). Resistance data were obtained with a Physical Property Measurement System (PPMS, Quantum Design).

2.2. Synthesis and crystallization

Single crystals of Sr₃Ni₂O₅Cl₂ were synthesized via high-pressure techniques using a stoichiometric mixture (1:1:1:2 molar ratio) of SrO₂, SrO, SrCl₂ and NiO in a Kawai-type multi-anvil press (Kawai et al., 1970 ). SrO₂ was prepared by precipitation from a reaction between Sr(NO₃)₂ and H₂O₂. Specifically, Sr(NO₃)₂ was dissolved in deionized water that had been pre-degassed by bubbling Ar gas through it to remove dissolved CO₂. A 30% aqueous H₂O₂ solution was then added, followed by aqueous NH₃ to induce precipitation. The precipitate was filtered off and dried at 423 K. All steps were carried out in a glove bag filled with argon gas to minimize CO₂ exposure. SrO was obtained by thermal decomposition of SrCO₃ at 1473 K under flowing argon gas, while SrCl₂ was prepared by dehydrating SrCl₂·6H₂O at 573 K under vacuum. The stoichiometric mixture was sealed in a Pt capsule inside an argon-filled glove box, heated to 1673 K at 10 GPa for 2 h in the press and then the temperature was reduced to room temperature by lowering it in 100 K increments, with a 20 min hold at each step, before releasing the pressure. The final product included single crystals with typical dimensions of 50 µm × 50 µm × 30 µm.

3. Results and discussion

Fig. 1 shows the SEM image of a representative crystal. The plate-like morphology is consistent with the layered structure typical of the Ruddlesden–Popper phase, indicating that the crystal readily cleaves along these planes. Notably, the depicted crystal was cleaved using Scotch tape, highlighting the inherent cleavage planes of the material. EDX analysis determined the composition to be Sr_3.05(2)Ni_2.13(4)O_xCl_1.81(1), in close agreement with the nominal stoichiometry of the starting materials.

Figure 1
SEM image of a single crystal of Sr₃Ni₂O₅Cl₂.

The parameters obtained from the SCXRD structure refinements are summarized in Tables 1 and 2. No significant deviations from full occupancy were observed for any of the atoms. Consequently, the crystal structure was determined to be isostructural with La₃Ni₂O₇ and Sr₃M₂O₅Cl₂ (M = Sc, Fe and Co) (Wang et al., 2024a, 2024b; Su et al., 2018 ; Leib et al., 1984 ; McGlothlin et al., 2000 ). Specifically, the compound crystallizes in the Ruddlesden–Popper phase structure, adopting the tetragonal I4/mmm symmetry, with lattice parameters a = 3.83990 (10) and c = 24.2936 (12) Å, as shown in Fig. 2(a).

Table 1
Experimental details

Crystal data
Chemical formula	Sr₃Ni₂O₅Cl₂
M_r	531.18
Crystal system, space group	Tetragonal, I4/mmm
Temperature (K)	301
a, c (Å)	3.8399 (1), 24.2936 (12)
V (Å³)	358.21 (3)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	28.06
Crystal size (mm)	0.03 × 0.03 × 0.02

Data collection
Diffractometer	Rigaku Synergy Custom DW diffractometer with a HyPix2000 detector
Absorption correction	Gaussian (CrysAlis PRO; Rigaku OD, 2024 $[Rigaku OD (2024). CrysAlis PRO. Rigaku Oxford Diffraction, Tokyo, Japan.]$ )
T_min, T_max	0.346, 0.380
No. of measured, independent and observed [I > 2σ(I)] reflections	8872, 500, 448
R_int	0.065
(sin θ/λ)_max (Å⁻¹)	0.992

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.029, 0.076, 1.12
No. of reflections	500
No. of parameters	18
Δρ_max, Δρ_min (e Å⁻³)	3.44, −1.03
Computer programs: CrysAlis PRO (Rigaku OD, 2024 $[Rigaku OD (2024). CrysAlis PRO. Rigaku Oxford Diffraction, Tokyo, Japan.]$ ), SHELXT2018 (Sheldrick, 2015a ), SHELXL2018 (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Table 2
Wyckoff positions (WP), occupancy (Occ), fractional atomic coordinates and isotropic and anisotropic atomic displacement parameters (Å²) of Sr₃Ni₂O₅Cl₂

Atom	WP	Occ	x	y	z	U_iso	U₁₁	U₂₂	U₃₃
Sr1	2a	1	0	0	0.5	0.01719 (12)	0.01381 (13)	= U₁₁	0.0239 (3)
Sr2	4e	1	0	0	0.34453 (2)	0.01499 (10)	0.01223 (10)	= U₁₁	0.02051 (19)
Ni	4e	1	0	0	0.07705 (2)	0.01226 (11)	0.01015 (13)	= U₁₁	0.01650 (2)
O_ap	2a	1	0	0	0	0.0193 (8)	0.02260 (12)	= U₁₁	0.01280 (17)
O_eq	8g	1	0	0.5	0.08818 (10)	0.0171 (4)	0.0156 (8)	0.0101 (7)	0.0256 (10)
Cl	4e	1	0	0	0.24750 (5)	0.0208 (2)	0.0181 (3)	= U₁₁	0.0263 (5)
Notes: (*) U₁₂ = U₁₃ = U₂₃ = 0.

Figure 2
The crystal structures of (a) Sr₃Ni₂O₅Cl₂ and (b) Sr₂NiO₃Cl (Tsujimoto et al., 2013

), and local coordination environments around (c) an Ni site and (d) Sr sites in the former compound and (e)/(f) those in the latter compound. The boxes in panels (a) and (b) represent unit cells. These figures were created with VESTA (Momma & Izumi, 2011

In the structure, there are two oxygen sites, 2a and 8g, referred to as O_ap and O_eq, respectively, in this article (Table 2). O_ap bridges two Ni atoms along the c axis, while O_eq is located between two Ni atoms in the ab plane. The bond lengths for Ni—O_ap, Ni—O_eq and Ni—Cl are 1.8719 (5), 1.9389 (4) and 3.1023 (14) Å, respectively. Based on these bond lengths, we have estimated the valence state of atoms using the bond valence sum (BVS) method (Brown et al., 1985 ; Brese et al., 1991 ). The BVS parameters of Ni²⁺—Cl⁻ of 2.02 was used (Brese et al., 1991), following a previous literature procedure for the related compound Sr₂NiO₃Cl (Tsujimoto et al., 2013 ).

The Ni valence was estimated to be +3.17. Similarly, the valences of Sr1 and Sr2 were estimated from the coordination environments, shown in Fig. 2(d), to be +1.83 and +2.57, respectively. These values are in reasonable agreement with the formal valence expected from the composition, considering that the structure is stabilized only under high-pressure conditions (Ochi et al., 2025). Another high-pressure phase of Ni oxide Sr₂NiO₃Cl (Tsujimoto et al., 2013) also exhibits a larger Sr valence (+2.51) at the Sr2 site, which is surrounded by both O and Cl ions, as shown in Fig. 2(f). The asymmetry in coordination may account for the higher BVS valences. In contrast, the Ni ions are displaced toward the O_ap ions from the centre of the O_eq coordination plane, reducing the Ni—O_eq—Ni bridging angle from 180 to 163.98 (15)° in Sr₃Ni₂O₅Cl₂. This value closely matches the theoretical prediction of 162°, further reinforcing the validity of the theoretical calculation.

Interestingly, the Ni—O_ap bond length is significantly shorter than the Ni—O_eq bond length. Although this trend is also observed in Sr₂NiO₃Cl, as shown in Fig. 2(e), it is more pronounced in Sr₃Ni₂O₅Cl₂. In fact, the ratio of Ni—O_ap to Ni—O_eq is 0.965 in Sr₃Ni₂O₅Cl₂, whereas the ratio for Sr₂NiO₃Cl is 0.975, suggesting stronger covalency between Ni—O_ap in Sr₃Ni₂O₅Cl₂ than in Sr₂NiO₃Cl. The larger displacement of the transition-metal cations toward O_ap in the double-layered structure, compared to the single-layered structure, may be a common characteristic feature of strontium transition-metal oxychlorides (Hector et al., 2001 ; Leib et al., 1984; Loureiro et al., 2000 ). Thus, the highly enhanced vertical interlayer hopping in Sr₃Ni₂O₅Cl₂ predicted by theory is presumably attributed to this feature of the strontium transition-metal oxychlorides, being related to the high covalence between the Ni and O_ap atoms.

The temperature dependences of electrical resistance under various pressures are shown in Fig. 3. Although the resistance increases with decreasing temperature at 0.2 GPa, which is almost ambient pressure, the compound remains relatively conductive, consistent with the metallic nature predicted by theory. However, no superconductivity is observed down to 2 K. The increase in resistance with decreasing temperature is gradually supressed by applying pressure up to 24 GPa, However, superconductivity does not emerge. The origin of the absence of superconductivity is under investigation.

Figure 3
Temperature dependence of the electrical resistance of Sr₃Ni₂O₅Cl₂ under various pressures.

Supporting information

CCDC reference: 2431174

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2053229625002281/dg3068sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2053229625002281/dg3068Isup2.hkl

Computing details top

Tristrontium dinickel pentaoxide dichloride top

Crystal data top

Sr₃Ni₂O₅Cl₂	D_x = 4.925 Mg m⁻³
M_r = 531.18	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I4/mmm	Cell parameters from 4484 reflections
a = 3.8399 (1) Å	θ = 3.3–44.7°
c = 24.2936 (12) Å	µ = 28.06 mm⁻¹
V = 358.21 (3) Å³	T = 301 K
Z = 2	Block, metallic black
F(000) = 488	0.03 × 0.03 × 0.02 mm

Data collection top

Rigaku Synergy Custom DW diffractometer with a HyPix2000 detector	500 independent reflections
Radiation source: Rotating-anode X-ray tube, Rigaku (Mo) X-ray Source	448 reflections with I > 2σ(I)
Mirror monochromator	R_int = 0.065
Detector resolution: 10.0000 pixels mm^-1	θ_max = 44.9°, θ_min = 3.4°
ω scans	h = −7→7
Absorption correction: gaussian (CrysAlis PRO; Rigaku OD, 2024)	k = −7→7
T_min = 0.346, T_max = 0.380	l = −48→48
8872 measured reflections

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Primary atom site location: dual
R[F² > 2σ(F²)] = 0.029	w = 1/[σ²(F_o²) + (0.0395P)² + 0.6699P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.076	(Δ/σ)_max = 0.001
S = 1.12	Δρ_max = 3.44 e Å⁻³
500 reflections	Δρ_min = −1.03 e Å⁻³
18 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Ni	−0.500000	−0.500000	0.42295 (2)	0.01226 (11)
O1	−0.500000	−0.500000	0.500000	0.0193 (8)
O2	−0.500000	−1.000000	0.41182 (10)	0.0171 (4)
Cl	−0.500000	−0.500000	0.29525 (5)	0.0208 (2)
Sr1	0.000000	0.000000	0.500000	0.01719 (12)
Sr2	−1.000000	−1.000000	0.34453 (2)	0.01499 (10)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni	0.01015 (13)	0.01015 (13)	0.0165 (2)	0.000	0.000	0.000
O1	0.0226 (12)	0.0226 (12)	0.0128 (17)	0.000	0.000	0.000
O2	0.0156 (8)	0.0101 (7)	0.0256 (10)	0.000	0.000	0.000
Cl	0.0181 (3)	0.0181 (3)	0.0263 (5)	0.000	0.000	0.000
Sr1	0.01381 (13)	0.01381 (13)	0.0239 (3)	0.000	0.000	0.000
Sr2	0.01223 (10)	0.01223 (10)	0.02051 (19)	0.000	0.000	0.000

Geometric parameters (Å, º) top

Ni—O1	1.8719 (5)	O1—Sr1^vi	2.7152 (1)
Ni—O2	1.9389 (3)	O1—Sr1^v	2.7152 (1)
Ni—O2ⁱ	1.9389 (4)	O1—Sr1^iv	2.7152 (1)
Ni—O2ⁱⁱ	1.9389 (4)	O2—Sr1^vi	2.8766 (18)
Ni—O2ⁱⁱⁱ	1.9389 (4)	O2—Sr1^iv	2.8766 (18)
Ni—Sr1	3.2980 (3)	O2—Sr2	2.5217 (16)
Ni—Sr1^iv	3.2980 (3)	O2—Sr2^viii	2.5218 (16)
Ni—Sr1^v	3.2980 (3)	Cl—Sr2^vii	2.9674 (6)
Ni—Sr1^vi	3.2980 (3)	Cl—Sr2^viii	2.9674 (6)
Ni—Sr2	3.3169 (4)	Cl—Sr2	2.9674 (6)
Ni—Sr2^vii	3.3169 (4)	Cl—Sr2^ix	3.3956 (13)
Ni—Sr2^viii	3.3169 (4)	Cl—Sr2ⁱⁱⁱ	2.9674 (6)
O1—Sr1	2.7152 (1)

O1—Ni—O2	98.01 (7)	O1—Sr1—O2^xiv	118.16 (2)
O1—Ni—O2ⁱ	98.01 (7)	O1^vii—Sr1—O2ⁱⁱⁱ	118.16 (2)
O1—Ni—O2ⁱⁱ	98.01 (7)	O1—Sr1—O2ⁱⁱ	61.84 (2)
O1—Ni—O2ⁱⁱⁱ	98.01 (7)	O1ⁱⁱⁱ—Sr1—O2ⁱⁱⁱ	61.84 (2)
O1—Ni—Sr1	55.417 (8)	O1—Sr1—O2ⁱⁱⁱ	61.84 (2)
O1—Ni—Sr1^vi	55.417 (8)	O1ⁱⁱⁱ—Sr1—O2ⁱⁱ	118.16 (2)
O1—Ni—Sr1^iv	55.417 (7)	O1—Sr1—O2^xiii	61.84 (2)
O1—Ni—Sr1^v	55.417 (8)	O1^viii—Sr1—O2ⁱⁱⁱ	118.16 (2)
O1—Ni—Sr2	125.055 (9)	O1^viii—Sr1—O2^xii	118.16 (2)
O1—Ni—Sr2^vii	125.056 (9)	O1^vii—Sr1—O2^x	118.16 (2)
O1—Ni—Sr2^viii	125.056 (9)	O1^viii—Sr1—O2^xiv	61.84 (2)
O2ⁱ—Ni—O2ⁱⁱ	163.98 (15)	O1ⁱⁱⁱ—Sr1—O2^x	61.84 (2)
O2—Ni—O2ⁱ	88.89 (2)	O1^viii—Sr1—O2^x	118.16 (2)
O2—Ni—O2ⁱⁱ	88.89 (2)	O1^vii—Sr1—O2^vii	61.84 (2)
O2ⁱ—Ni—O2ⁱⁱⁱ	88.89 (2)	O1—Sr1—O2^x	61.84 (2)
O2—Ni—O2ⁱⁱⁱ	163.98 (15)	O1ⁱⁱⁱ—Sr1—O2^vii	118.16 (2)
O2ⁱⁱ—Ni—O2ⁱⁱⁱ	88.89 (2)	O1^viii—Sr1—O2^vii	61.84 (2)
O2ⁱ—Ni—Sr1^v	60.17 (5)	O1^vii—Sr1—O2^xiii	118.16 (2)
O2—Ni—Sr1	130.96 (5)	O1—Sr1—O2^xi	118.16 (2)
O2ⁱⁱ—Ni—Sr1^v	130.96 (5)	O1ⁱⁱⁱ—Sr1—O2^xiii	118.16 (2)
O2ⁱ—Ni—Sr1	130.96 (5)	O1—Sr1—O2^vii	118.16 (2)
O2—Ni—Sr1^vi	60.17 (5)	O1^vii—Sr1—O2^xii	61.84 (2)
O2ⁱⁱ—Ni—Sr1	60.17 (5)	O1ⁱⁱⁱ—Sr1—O2^xiv	118.16 (2)
O2ⁱⁱ—Ni—Sr1^vi	60.17 (5)	O1ⁱⁱⁱ—Sr1—O2^xii	61.84 (2)
O2ⁱ—Ni—Sr1^vi	130.96 (5)	O1^vii—Sr1—O2^xiv	61.84 (2)
O2ⁱⁱⁱ—Ni—Sr1^v	60.17 (5)	O2^xiv—Sr1—O2ⁱⁱⁱ	180.0
O2ⁱⁱⁱ—Ni—Sr1^vi	130.96 (5)	O2^xi—Sr1—O2ⁱⁱⁱ	123.68 (4)
O2ⁱ—Ni—Sr1^iv	60.17 (5)	O2^xiv—Sr1—O2^xiii	56.32 (4)
O2ⁱⁱ—Ni—Sr1^iv	130.96 (5)	O2ⁱⁱ—Sr1—O2^xiv	123.68 (4)
O2ⁱⁱⁱ—Ni—Sr1^iv	130.96 (5)	O2ⁱⁱⁱ—Sr1—O2^vii	83.74 (7)
O2—Ni—Sr1^iv	60.17 (5)	O2ⁱⁱ—Sr1—O2ⁱⁱⁱ	56.32 (4)
O2—Ni—Sr1^v	130.96 (5)	O2^xiv—Sr1—O2^xii	123.68 (4)
O2ⁱⁱⁱ—Ni—Sr1	60.17 (5)	O2ⁱⁱⁱ—Sr1—O2^xiii	123.68 (4)
O2ⁱⁱⁱ—Ni—Sr2	119.55 (6)	O2ⁱⁱⁱ—Sr1—O2^xii	56.32 (4)
O2—Ni—Sr2	49.21 (5)	O2^xi—Sr1—O2^x	56.32 (4)
O2ⁱⁱ—Ni—Sr2	119.55 (6)	O2^xiii—Sr1—O2^xii	180.0
O2—Ni—Sr2^vii	119.55 (6)	O2^xiv—Sr1—O2^x	83.74 (7)
O2ⁱ—Ni—Sr2^viii	119.55 (6)	O2ⁱⁱⁱ—Sr1—O2^x	96.26 (7)
O2ⁱ—Ni—Sr2	49.21 (5)	O2^xi—Sr1—O2^xiv	56.32 (4)
O2—Ni—Sr2^viii	49.21 (5)	O2^xi—Sr1—O2^xii	96.26 (7)
O2ⁱⁱⁱ—Ni—Sr2^viii	119.55 (6)	O2ⁱⁱ—Sr1—O2^xiii	96.26 (7)
O2ⁱⁱ—Ni—Sr2^viii	49.21 (5)	O2^xi—Sr1—O2^vii	123.68 (4)
O2ⁱ—Ni—Sr2^vii	119.55 (6)	O2^xi—Sr1—O2^xiii	83.74 (7)
O2ⁱⁱⁱ—Ni—Sr2^vii	49.21 (5)	O2ⁱⁱ—Sr1—O2^vii	56.32 (4)
O2ⁱⁱ—Ni—Sr2^vii	49.21 (5)	O2^xiv—Sr1—O2^vii	96.26 (7)
Sr1^v—Ni—Sr1^iv	71.206 (7)	O2^xiii—Sr1—O2^vii	123.68 (4)
Sr1^vi—Ni—Sr1^iv	71.206 (7)	O2ⁱⁱ—Sr1—O2^x	123.68 (4)
Sr1^v—Ni—Sr1^vi	110.833 (15)	O2ⁱⁱ—Sr1—O2^xii	83.74 (7)
Sr1—Ni—Sr1^v	71.206 (7)	O2^xii—Sr1—O2^vii	56.32 (4)
Sr1—Ni—Sr1^vi	71.206 (7)	O2^xiii—Sr1—O2^x	56.32 (4)
Sr1—Ni—Sr1^iv	110.833 (15)	O2^x—Sr1—O2^vii	180.0
Sr1^v—Ni—Sr2^vii	109.027 (3)	O2^xii—Sr1—O2^x	123.68 (4)
Sr1^vi—Ni—Sr2^viii	69.639 (7)	O2^xi—Sr1—O2ⁱⁱ	180.0
Sr1—Ni—Sr2	179.528 (15)	Ni^v—Sr2—Ni^iv	70.737 (9)
Sr1^v—Ni—Sr2	109.027 (3)	Ni^vi—Sr2—Ni^iv	70.737 (9)
Sr1^iv—Ni—Sr2	69.638 (7)	Ni—Sr2—Ni^v	70.737 (9)
Sr1^iv—Ni—Sr2^vii	179.528 (15)	Ni—Sr2—Ni^vi	70.737 (9)
Sr1—Ni—Sr2^vii	69.639 (7)	Ni^v—Sr2—Ni^vi	109.889 (18)
Sr1—Ni—Sr2^viii	109.027 (3)	Ni—Sr2—Ni^iv	109.889 (18)
Sr1^v—Ni—Sr2^viii	179.528 (15)	O2—Sr2—Ni^iv	93.92 (4)
Sr1^iv—Ni—Sr2^viii	109.027 (3)	O2—Sr2—Ni^v	93.92 (4)
Sr1^vi—Ni—Sr2^vii	109.027 (3)	O2^xv—Sr2—Ni^vi	35.602 (6)
Sr1^vi—Ni—Sr2	109.027 (3)	O2ⁱ—Sr2—Ni^vi	93.92 (4)
Sr2—Ni—Sr2^viii	70.737 (9)	O2^xv—Sr2—Ni^v	93.92 (4)
Sr2—Ni—Sr2^vii	109.889 (18)	O2ⁱ—Sr2—Ni^iv	93.92 (4)
Sr2^vii—Ni—Sr2^viii	70.737 (9)	O2^v—Sr2—Ni^iv	35.602 (6)
Ni^x—O1—Ni	180.0	O2—Sr2—Ni	35.602 (6)
Ni—O1—Sr1^iv	90.0	O2^xv—Sr2—Ni	93.92 (4)
Ni^x—O1—Sr1^v	90.0	O2^xv—Sr2—Ni^iv	35.602 (6)
Ni^x—O1—Sr1^vi	90.0	O2^v—Sr2—Ni^v	35.602 (6)
Ni^x—O1—Sr1	90.0	O2ⁱ—Sr2—Ni	35.602 (6)
Ni—O1—Sr1^v	90.0	O2^v—Sr2—Ni	93.92 (4)
Ni—O1—Sr1^vi	90.0	O2ⁱ—Sr2—Ni^v	35.602 (6)
Ni^x—O1—Sr1^iv	90.0	O2—Sr2—Ni^vi	35.602 (6)
Ni—O1—Sr1	90.0	O2^v—Sr2—Ni^vi	93.92 (4)
Sr1^v—O1—Sr1^vi	180.0	O2^v—Sr2—O2	99.17 (9)
Sr1—O1—Sr1^vi	90.0	O2ⁱ—Sr2—O2^v	65.14 (5)
Sr1^iv—O1—Sr1	180.0	O2ⁱ—Sr2—O2^xv	99.17 (9)
Sr1^iv—O1—Sr1^vi	90.0	O2ⁱ—Sr2—O2	65.14 (5)
Sr1—O1—Sr1^v	90.0	O2^xv—Sr2—O2	65.14 (5)
Sr1^iv—O1—Sr1^v	90.0	O2^xv—Sr2—O2^v	65.14 (5)
Ni—O2—Ni^vi	163.98 (15)	O2^v—Sr2—Cl	138.952 (17)
Ni^vi—O2—Sr1^vi	84.04 (6)	O2ⁱ—Sr2—Cl^iv	138.952 (17)
Ni^vi—O2—Sr1^iv	84.04 (6)	O2—Sr2—Cl	76.64 (4)
Ni—O2—Sr1^iv	84.04 (6)	O2ⁱ—Sr2—Cl	76.64 (4)
Ni—O2—Sr1^vi	84.04 (6)	O2^v—Sr2—Cl^v	76.64 (4)
Ni—O2—Sr2	95.18 (4)	O2^v—Sr2—Cl^iv	76.64 (4)
Ni—O2—Sr2^viii	95.18 (4)	O2—Sr2—Cl^iv	138.952 (17)
Ni^vi—O2—Sr2	95.18 (4)	O2^xv—Sr2—Cl^iv	76.64 (4)
Ni^vi—O2—Sr2^viii	95.18 (4)	O2—Sr2—Cl^vi	76.64 (4)
Sr1^vi—O2—Sr1^iv	83.74 (7)	O2^xv—Sr2—Cl^vi	76.64 (4)
Sr2—O2—Sr1^iv	88.546 (13)	O2ⁱ—Sr2—Cl^v	76.64 (4)
Sr2^viii—O2—Sr1^iv	172.29 (8)	O2^v—Sr2—Cl^vi	138.952 (17)
Sr2—O2—Sr1^vi	172.28 (8)	O2ⁱ—Sr2—Cl^vi	138.952 (17)
Sr2^viii—O2—Sr1^vi	88.547 (13)	O2^xv—Sr2—Cl^v	138.952 (17)
Sr2—O2—Sr2^viii	99.17 (9)	O2^xv—Sr2—Cl	138.952 (17)
Sr2^vii—Cl—Sr2ⁱⁱⁱ	80.635 (18)	O2—Sr2—Cl^v	138.952 (17)
Sr2ⁱⁱⁱ—Cl—Sr2	80.634 (18)	Cl^iv—Sr2—Ni	168.74 (3)
Sr2^viii—Cl—Sr2	80.634 (18)	Cl^iv—Sr2—Ni^iv	58.85 (2)
Sr2ⁱⁱⁱ—Cl—Sr2^ix	113.79 (2)	Cl^vi—Sr2—Ni^v	168.74 (3)
Sr2—Cl—Sr2^ix	113.79 (2)	Cl—Sr2—Ni^vi	103.398 (13)
Sr2^vii—Cl—Sr2^viii	80.635 (18)	Cl^v—Sr2—Ni^iv	103.398 (13)
Sr2ⁱⁱⁱ—Cl—Sr2^viii	132.42 (5)	Cl—Sr2—Ni^v	103.398 (13)
Sr2^vii—Cl—Sr2^ix	113.79 (2)	Cl^vi—Sr2—Ni^iv	103.398 (13)
Sr2^vii—Cl—Sr2	132.42 (5)	Cl^iv—Sr2—Ni^v	103.398 (13)
Sr2^viii—Cl—Sr2^ix	113.79 (2)	Cl^v—Sr2—Ni^vi	168.74 (3)
O1^vii—Sr1—O1	180.0	Cl^v—Sr2—Ni	103.397 (13)
O1—Sr1—O1ⁱⁱⁱ	90.0	Cl^iv—Sr2—Ni^vi	103.398 (13)
O1—Sr1—O1^viii	90.0	Cl^vi—Sr2—Ni^vi	58.85 (2)
O1^vii—Sr1—O1^viii	90.0	Cl—Sr2—Ni	58.85 (2)
O1ⁱⁱⁱ—Sr1—O1^viii	180.0	Cl—Sr2—Ni^iv	168.74 (3)
O1^vii—Sr1—O1ⁱⁱⁱ	90.0	Cl^v—Sr2—Ni^v	58.85 (2)
O1^vii—Sr1—O2^xi	61.84 (2)	Cl^vi—Sr2—Ni	103.397 (13)
O1—Sr1—O2^xii	118.16 (2)	Cl^v—Sr2—Cl^vi	132.42 (5)
O1^viii—Sr1—O2^xi	118.16 (2)	Cl^iv—Sr2—Cl^vi	80.634 (18)
O1^vii—Sr1—O2ⁱⁱ	118.16 (2)	Cl—Sr2—Cl^v	80.634 (18)
O1ⁱⁱⁱ—Sr1—O2^xi	61.84 (2)	Cl—Sr2—Cl^vi	80.634 (18)
O1^viii—Sr1—O2ⁱⁱ	61.84 (2)	Cl^iv—Sr2—Cl^v	80.634 (18)
O1^viii—Sr1—O2^xiii	61.84 (2)	Cl^iv—Sr2—Cl	132.42 (5)

O2—Ni—O1—Sr1^iv	−45.0	Sr1^iv—Ni—O1—Sr1^vi	90.0
O2—Ni—O1—Sr1^v	−135.0	Sr1^vi—Ni—O1—Sr1^v	180.0
O2ⁱⁱⁱ—Ni—O1—Sr1^iv	135.0	Sr1—Ni—O1—Sr1^vi	−90.0
O2—Ni—O1—Sr1	135.0	Sr1^v—Ni—O1—Sr1	−90.0
O2ⁱⁱ—Ni—O1—Sr1^iv	−135.0	Sr1—Ni—O1—Sr1^v	90.0
O2ⁱⁱⁱ—Ni—O1—Sr1	−45.0	Sr1^vi—Ni—O1—Sr1^iv	−90.0
O2—Ni—O1—Sr1^vi	45.0	Sr1^iv—Ni—O1—Sr1	180.0
O2ⁱⁱⁱ—Ni—O1—Sr1^vi	−135.0	Sr1^vi—Ni—O1—Sr1	90.0
O2ⁱ—Ni—O1—Sr1^v	−45.0	Sr2^vii—Ni—O1—Sr1^v	90.0
O2ⁱ—Ni—O1—Sr1	−135.0	Sr2^viii—Ni—O1—Sr1^iv	−90.0
O2ⁱⁱ—Ni—O1—Sr1^v	135.0	Sr2^viii—Ni—O1—Sr1^v	180.0
O2ⁱⁱⁱ—Ni—O1—Sr1^v	45.0	Sr2^vii—Ni—O1—Sr1	0.0
O2ⁱ—Ni—O1—Sr1^iv	45.0	Sr2^vii—Ni—O1—Sr1^vi	−90.0
O2ⁱⁱ—Ni—O1—Sr1	45.0	Sr2—Ni—O1—Sr1	180.0
O2ⁱ—Ni—O1—Sr1^vi	135.0	Sr2^vii—Ni—O1—Sr1^iv	180.0
O2ⁱⁱ—Ni—O1—Sr1^vi	−45.0	Sr2—Ni—O1—Sr1^vi	90.0
Sr1—Ni—O1—Sr1^iv	180.0	Sr2^viii—Ni—O1—Sr1^vi	0.0
Sr1^iv—Ni—O1—Sr1^v	−90.0	Sr2^viii—Ni—O1—Sr1	90.0
Sr1^v—Ni—O1—Sr1^vi	180.0	Sr2—Ni—O1—Sr1^v	−90.0
Sr1^v—Ni—O1—Sr1^iv	90.0	Sr2—Ni—O1—Sr1^iv	0.0

Symmetry codes: (i) −y−2, x, z; (ii) −y−1, x, z; (iii) x, y+1, z; (iv) x−1, y−1, z; (v) x−1, y, z; (vi) x, y−1, z; (vii) x+1, y+1, z; (viii) x+1, y, z; (ix) −x−3/2, −y−3/2, −z+1/2; (x) −x−1, −y−1, −z+1; (xi) y+1, −x, −z+1; (xii) −y−1, x+1, z; (xiii) y+1, −x−1, −z+1; (xiv) −x, −y−1, −z+1; (xv) −y−2, x−1, z.

Wyckoff positions (WP), occupancy, fractional atomic coordinates, isotropic and anisotropic atomic displacement parameters (Å²) of Sr₃Ni₂O₅Cl₂ top

Atom	WP	Occ.	x	y	z	U_iso	U₁₁	U₂₂	U₃₃
Sr1	2a	1	0	0	0.5	0.01719 (12)	0.01381 (13)	= U₁₁	0.0239 (3)
Sr2	4e	1	0	0	0.34453 (2)	0.01499 (10)	0.01223 (10)	= U₁₁	0.02051 (19)
Ni	4e	1	0	0	0.07705 (2)	0.01226 (11)	0.01015 (13)	= U₁₁	0.01650 (2)
O_ap	2a	1	0	0	0	0.0193 (8)	0.02260 (12)	= U₁₁	0.01280 (17)
O_eq	8g	1	0	0.5	0.08818 (10)	0.0171 (4)	0.0156 (8)	0.0101 (7)	0.0256 (10)
Cl	4e	1	0	0	0.24750 (5)	0.0208 (2)	0.0181 (3)	= U₁₁	0.0263 (5)

Notes: (*) U₁₂ = U₁₃ = U₂₃ = 0.

Acknowledgements

We thank Professors Masayuki Ochi (Osaka University), Hirofumi Sakakibara (Tottori University), Hidetomo Usui (Shimane Univsity) and Kazuhiko Kuroki (Osaka University) for fruitful discussions. This work is supported by the World Premier International Research Center Initiative (WPI), MEXT, Japan, and JSPS KAKENHI.

Conflict of interest

The authors declare no competing interests.

Data availability

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.

Funding information

Funding for this research was provided by: World Premier International Research Center Initiative (grant No. JP20H05644); JSPS KAKENHI (grant No. JP24K01333).

References

Brese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192–197. CrossRef CAS Web of Science IUCr Journals Google Scholar
Brown, I. D. & Altermatt, D. (1985). Acta Cryst. B41, 244–247. CrossRef CAS Web of Science IUCr Journals Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hector, A. L., Hutchings, J. A., Needs, R. L., Thomas, M. F. & Weller, M. T. (2001). J. Mater. Chem. 11, 527–532. CrossRef ICSD CAS Google Scholar
Kaneko, T., Sakakibara, H., Ochi, M. & Kuroki, K. (2024). Phys. Rev. B, 109, 045154. CrossRef Google Scholar
Kawai, N. & Endo, S. (1970). Rev. Sci. Instrum. 41, 1178–1181. CrossRef CAS Google Scholar
Leib, W. & Müller–Buschbaum, Hk. (1984). Z. Anorg. Allg. Chem. 518, 115–119. CrossRef ICSD CAS Google Scholar
Loureiro, S. M., Felser, C., Huang, Q. & Cava, R. J. (2000). Chem. Mater. 12, 3181–3185. CrossRef ICSD CAS Google Scholar
Matsumoto, R., Sasama, Y., Fujioka, M., Irifune, T., Tanaka, M., Yamaguchi, T., Takeya, H. & Takano, Y. (2016). Rev. Sci. Instrum. 87, 076103. CrossRef PubMed Google Scholar
McGlothlin, N., Ho, D. & Cava, R. J. (2000). Mater. Res. Bull. 35, 1035–1043. CrossRef ICSD CAS Google Scholar
Momma, K. & Izumi, F. (2011). J. Appl. Cryst. 44, 1272–1276. Web of Science CrossRef CAS IUCr Journals Google Scholar
Nagata, H., Sakurai, H., Ueki, Y., Yamane, K., Matsumoto, R., Terashima, K., Hirose, K., Ohta, H., Kato, M. & Takano, Y. (2024). J. Phys. Soc. Jpn, 93, 095003. CrossRef Google Scholar
Nakata, M., Ogura, D., Usui, H. & Kuroki, K. (2017). Phys. Rev. B, 95, 214509. CrossRef Google Scholar
Ochi, M., Sakakibara, H., Usui, H. & Kuroki, K. (2025). Phys. Rev. B, 111, 064511. CrossRef Google Scholar
Rigaku OD (2024). CrysAlis PRO. Rigaku Oxford Diffraction, Tokyo, Japan. Google Scholar
Sakakibara, H., Kitamine, N., Ochi, M. & Kuroki, K. (2024a). Phys. Rev. Lett. 132, 106002. CrossRef PubMed Google Scholar
Sakakibara, H., Ochi, M., Nagata, H., Ueki, Y., Sakurai, H., Matsumoto, R., Terashima, K., Hirose, K., Ohta, H., Kato, M., Takano, Y. & Kuroki, K. (2024b). Phys. Rev. B, 109, 144511. CrossRef Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Su, Y., Tsujimoto, Y., Fujii, K., Tatsuta, M., Oka, K., Yashima, M., Ogino, H. & Yamaura, K. (2018). Inorg. Chem. 57, 5615–5623. Web of Science CrossRef ICSD CAS PubMed Google Scholar
Sun, H., Huo, M., Hu, X., Li, J., Liu, Z., Han, Y., Tang, L., Mao, Z., Yang, P., Wang, B., Cheng, J., Yao, D. X., Zhang, G. M. & Wang, M. (2023). Nature, 621, 493–498. CrossRef CAS PubMed Google Scholar
Tsujimoto, Y., Yamaura, K. & Uchikoshi, T. (2013). Inorg. Chem. 52, 10211–10216. CrossRef ICSD CAS PubMed Google Scholar
Ueki, Y., Sakurai, H., Nagata, H., Yamane, K., Matsumoto, R., Terashima, K., Hirose, K., Ohta, H., Kato, M. & Takano, Y. (2024). arXiv preprint arXiv:2408.04970. Google Scholar
Wang, L., Li, Y., Xie, S. Y., Liu, F., Sun, H., Huang, C., Gao, Y., Nakagawa, T., Fu, B., Dong, B., Cao, Z., Yu, R., Kawaguchi, S. I., Kadobayashi, H., Wang, M., Jin, C., Mao, H. K. & Liu, H. (2024a). J. Am. Chem. Soc. 146, 7506–7514. CrossRef ICSD CAS PubMed Google Scholar
Wang, N., Wang, G., Shen, X., Hou, J., Luo, J., Ma, X., Yang, H., Shi, L., Dou, J., Feng, J., Yang, J., Shi, Y., Ren, Z., Ma, H., Yang, P., Liu, Y., Liu, Y., Zhang, H., Dong, X., Wang, Y., Jiang, K., Hu, J., Nagasaki, S., Kitagawa, K., Calder, S., Yan, J., Sun, J., Wang, B., Zhou, R., Uwatoko, Y. & Cheng, J. (2024b). Nature, 634, 579–584. CrossRef CAS PubMed Google Scholar

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Volume 81| Part 5| May 2025| Pages 259-263

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