Promising solid electrolyte material for an IT-SOFC: crystal structure of the cerium gadolinium holmium oxide Ce_0.8Gd_0.1Ho_0.1O_1.9 between 295 and 1023 K

The crystal structure of Ce_0.8Gd_0.1Ho_0.1O_1.9 (cerium gadolinium holmium oxide) has been determined from powder X-ray diffraction data. This is a promising material for application as a solid electrolyte for inter­mediate-temperature solid oxide fuel cells (IT-SOFCs). Nanoparticles were prepared using a novel sodium alginate sol-gel method, where the sodium ion was exchanged with ions of inter­est and, after washing, the gel was calcined at 723 K in air. The crystallographic features of Gd and Ho co-doped cerium oxide were investigated around the desired operating temperatures of IT-SOFCs, i.e. 573 ≤ T ≤ 1023 K. We find that the crystal structure is a stable fluorite structure with the space group Fmm in the entire temperature range. In addition, the trend in lattice parameters shows that there is a monotonic increase with increasing temperature.

Computing details

Program(s) used to refine structure: GSAS (Larson & Von Dreele, 2004); software used to prepare material for publication: enCIFer (Allen et al., 2004).

Cerium gadolinium holmium oxide

Crystal data

Ce0.8Gd0.1Ho0.1O1.9	Z = 4
Mr = 174.71	Cu Kα radiation, λ = 1.5418 Å
Cubic, Fm3m	T = 298 K
Hall symbol: -F 4 2 3	Particle morphology: powder
a = 5.4214 (7) Å	pale yellow
V = 159.34 (6) Å^3	Specimen preparation: Prepared at 973 K and 0 kPa, cooled at 1 K min^−1

Data collection

PANalytical X'Pert XRD diffractometer	Data collection mode: reflection
Cu monochromator	Scan method: step
Specimen mounting: flat plate holder	2θmin = 9.878°, 2θmax = 99.803°, 2θstep = 0.033°

Refinement

Least-squares matrix: full	Profile function: CW Profile function number 4 with 14 terms Pseudovoigt profile coefficients as parameterized in P. Thompson, D.E. Cox & J.B. Hastings (1987). J. Appl. Cryst.,20,79-83. Asymmetry correction of L.W. Finger, D.E. Cox & A. P. Jephcoat (1994). J. Appl. Cryst.,27,892-900. Microstrain broadening by P.W. Stephens, (1999). J. Appl. Cryst.,32,281-289. #1(GU) = 1127.450 #2(GV) = ******** #3(GW) = 2992.640 #4(GP) = 1256.950 #5(LX) = 46.702 #6(ptec) = 3.53 #7(trns) = 0.00 #8(shft) = 0.0000 #9(sfec) = 0.00 #10(S/L) = 0.0050 #11(H/L) = 0.0005 #12(eta) = 0.0000 #13(S400 ) = 0.0E+00 #14(S220 ) = 0.0E+00 Peak tails are ignored where the intensity is below 0.0001 times the peak Aniso. broadening axis 0.0 0.0 1.0
Rp = 0.041	24 parameters
Rwp = 0.052	0 restraints
Rexp = 0.044	(Δ/σ)max = 0.03
R(F^2) = 0.04859	Background function: GSAS Background function number 1 with 20 terms. Shifted Chebyshev function of 1st kind 1: 395.922 2: 128.091 3: -7.03946 4: 6.67325 5: -3.29283 6: 0.252425 7: -3.28895 8: 3.40089 9: 3.97722 10: -3.25194 11: -7.20781 12: -4.57777 13: 5.00053 14: 1.86540 15: -8.02642 16: -5.79388 17: 0.967461 18: -2.36138 19: 4.35414 20: -0.667179

Special details

Refinement. Resolution

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
CE1	0.0	0.0	0.0	0.00304*	0.8
HO1	0.0	0.0	0.0	0.00304*	0.1
GD1	0.0	0.0	0.0	0.00304*	0.1
O1	0.25	0.25	0.25	0.00051*	0.95

Geometric parameters (Å, º)

CE1—CE1^i	3.8335 (4)	GD1—HO1^v	3.8335 (4)
CE1—CE1^ii	3.8335 (4)	GD1—HO1^vi	3.8335 (4)
CE1—CE1^iii	3.8335 (4)	GD1—HO1^vii	3.8335 (4)
CE1—CE1^iv	3.8335 (4)	GD1—HO1^viii	3.8335 (4)
CE1—CE1^v	3.8335 (4)	GD1—HO1^ix	3.8335 (5)
CE1—CE1^vi	3.8335 (4)	GD1—HO1^x	3.8335 (5)
CE1—CE1^vii	3.8335 (4)	GD1—HO1^xi	3.8335 (5)
CE1—CE1^viii	3.8335 (4)	GD1—HO1^xii	3.8335 (5)
CE1—CE1^ix	3.8335 (5)	GD1—O1	2.3475 (2)
CE1—CE1^x	3.8335 (5)	GD1—O1^xiii	2.3475 (2)
CE1—CE1^xi	3.8335 (5)	GD1—O1^xiv	2.3475 (2)
CE1—CE1^xii	3.8335 (5)	GD1—O1^xv	2.3475 (2)
CE1—GD1^i	3.8335 (4)	GD1—O1^xvi	2.3475 (2)
CE1—GD1^ii	3.8335 (4)	GD1—O1^xvii	2.3475 (2)
CE1—GD1^iii	3.8335 (4)	GD1—O1^xviii	2.3475 (2)
CE1—GD1^iv	3.8335 (4)	GD1—O1^xix	2.3475 (2)
CE1—GD1^v	3.8335 (4)	HO1—CE1^i	3.8335 (4)
CE1—GD1^vi	3.8335 (4)	HO1—CE1^ii	3.8335 (4)
CE1—GD1^vii	3.8335 (4)	HO1—CE1^iii	3.8335 (4)
CE1—GD1^viii	3.8335 (4)	HO1—CE1^iv	3.8335 (4)
CE1—GD1^ix	3.8335 (5)	HO1—CE1^v	3.8335 (4)
CE1—GD1^x	3.8335 (5)	HO1—CE1^vi	3.8335 (4)
CE1—GD1^xi	3.8335 (5)	HO1—CE1^vii	3.8335 (4)
CE1—GD1^xii	3.8335 (5)	HO1—CE1^viii	3.8335 (4)
CE1—HO1^i	3.8335 (4)	HO1—CE1^ix	3.8335 (5)
CE1—HO1^ii	3.8335 (4)	HO1—CE1^x	3.8335 (5)
CE1—HO1^iii	3.8335 (4)	HO1—CE1^xi	3.8335 (5)
CE1—HO1^iv	3.8335 (4)	HO1—CE1^xii	3.8335 (5)
CE1—HO1^v	3.8335 (4)	HO1—GD1^i	3.8335 (4)
CE1—HO1^vi	3.8335 (4)	HO1—GD1^ii	3.8335 (4)
CE1—HO1^vii	3.8335 (4)	HO1—GD1^iii	3.8335 (4)
CE1—HO1^viii	3.8335 (4)	HO1—GD1^iv	3.8335 (4)
CE1—HO1^ix	3.8335 (5)	HO1—GD1^v	3.8335 (4)
CE1—HO1^x	3.8335 (5)	HO1—GD1^vi	3.8335 (4)
CE1—HO1^xi	3.8335 (5)	HO1—GD1^vii	3.8335 (4)
CE1—HO1^xii	3.8335 (5)	HO1—GD1^viii	3.8335 (4)
CE1—O1	2.3475 (2)	HO1—GD1^ix	3.8335 (5)
CE1—O1^xiii	2.3475 (2)	HO1—GD1^x	3.8335 (5)
CE1—O1^xiv	2.3475 (2)	HO1—GD1^xi	3.8335 (5)
CE1—O1^xv	2.3475 (2)	HO1—GD1^xii	3.8335 (5)
CE1—O1^xvi	2.3475 (2)	HO1—HO1^i	3.8335 (4)
CE1—O1^xvii	2.3475 (2)	HO1—HO1^ii	3.8335 (4)
CE1—O1^xviii	2.3475 (2)	HO1—HO1^iii	3.8335 (4)
CE1—O1^xix	2.3475 (2)	HO1—HO1^iv	3.8335 (4)
GD1—CE1^i	3.8335 (4)	HO1—HO1^v	3.8335 (4)
GD1—CE1^ii	3.8335 (4)	HO1—HO1^vi	3.8335 (4)
GD1—CE1^iii	3.8335 (4)	HO1—HO1^vii	3.8335 (4)
GD1—CE1^iv	3.8335 (4)	HO1—HO1^viii	3.8335 (4)
GD1—CE1^v	3.8335 (4)	HO1—HO1^ix	3.8335 (5)
GD1—CE1^vi	3.8335 (4)	HO1—HO1^x	3.8335 (5)
GD1—CE1^vii	3.8335 (4)	HO1—HO1^xi	3.8335 (5)
GD1—CE1^viii	3.8335 (4)	HO1—HO1^xii	3.8335 (5)
GD1—CE1^ix	3.8335 (5)	HO1—O1	2.3475 (2)
GD1—CE1^x	3.8335 (5)	HO1—O1^xiii	2.3475 (2)
GD1—CE1^xi	3.8335 (5)	HO1—O1^xiv	2.3475 (2)
GD1—CE1^xii	3.8335 (5)	HO1—O1^xv	2.3475 (2)
GD1—GD1^i	3.8335 (4)	HO1—O1^xvi	2.3475 (2)
GD1—GD1^ii	3.8335 (4)	HO1—O1^xvii	2.3475 (2)
GD1—GD1^iii	3.8335 (4)	HO1—O1^xviii	2.3475 (2)
GD1—GD1^iv	3.8335 (4)	HO1—O1^xix	2.3475 (2)
GD1—GD1^v	3.8335 (4)	O1—CE1	2.3475 (2)
GD1—GD1^vi	3.8335 (4)	O1—CE1^iv	2.3475 (2)
GD1—GD1^vii	3.8335 (4)	O1—CE1^viii	2.3475 (2)
GD1—GD1^viii	3.8335 (4)	O1—CE1^xii	2.3475 (2)
GD1—GD1^ix	3.8335 (5)	O1—GD1	2.3475 (2)
GD1—GD1^x	3.8335 (5)	O1—GD1^iv	2.3475 (2)
GD1—GD1^xi	3.8335 (5)	O1—GD1^viii	2.3475 (2)
GD1—GD1^xii	3.8335 (5)	O1—GD1^xii	2.3475 (2)
GD1—HO1^i	3.8335 (4)	O1—HO1	2.3475 (2)
GD1—HO1^ii	3.8335 (4)	O1—HO1^iv	2.3475 (2)
GD1—HO1^iii	3.8335 (4)	O1—HO1^viii	2.3475 (2)
GD1—HO1^iv	3.8335 (4)	O1—HO1^xii	2.3475 (2)
O1—CE1—O1^xiii	70.529 (10)	O1^xv—HO1—O1^xvii	70.529 (5)
O1—CE1—O1^xiv	70.529 (5)	O1^xv—HO1—O1^xviii	70.529 (10)
O1—CE1—O1^xv	70.529 (5)	O1^xv—HO1—O1^xix	109.471 (5)
O1—CE1—O1^xvi	109.471 (5)	O1^xvi—HO1—O1^xvii	109.471 (5)
O1—CE1—O1^xvii	109.471 (10)	O1^xvi—HO1—O1^xviii	109.471 (10)
O1—CE1—O1^xviii	109.471 (5)	O1^xvi—HO1—O1^xix	70.529 (5)
O1—CE1—O1^xix	180.0	O1^xvii—HO1—O1^xviii	109.471 (5)
O1^xiii—CE1—O1^xiv	109.471 (5)	O1^xvii—HO1—O1^xix	70.529 (10)
O1^xiii—CE1—O1^xv	109.471 (5)	O1^xviii—HO1—O1^xix	70.529 (5)
O1^xiii—CE1—O1^xvi	70.529 (5)	CE1—O1—CE1^iv	109.471 (5)
O1^xiii—CE1—O1^xvii	180.0	CE1—O1—CE1^viii	109.471 (5)
O1^xiii—CE1—O1^xviii	70.529 (5)	CE1—O1—CE1^xii	109.471 (10)
O1^xiii—CE1—O1^xix	109.471 (10)	CE1—O1—GD1	0.0
O1^xiv—CE1—O1^xv	109.471 (10)	CE1—O1—GD1^iv	109.471 (5)
O1^xiv—CE1—O1^xvi	70.529 (10)	CE1—O1—GD1^viii	109.471 (5)
O1^xiv—CE1—O1^xvii	70.529 (5)	CE1—O1—GD1^xii	109.471 (10)
O1^xiv—CE1—O1^xviii	180.0	CE1—O1—HO1	0.0
O1^xiv—CE1—O1^xix	109.471 (5)	CE1—O1—HO1^iv	109.471 (5)
O1^xv—CE1—O1^xvi	180.0	CE1—O1—HO1^viii	109.471 (5)
O1^xv—CE1—O1^xvii	70.529 (5)	CE1—O1—HO1^xii	109.471 (10)
O1^xv—CE1—O1^xviii	70.529 (10)	CE1^iv—O1—CE1^viii	109.471 (10)
O1^xv—CE1—O1^xix	109.471 (5)	CE1^iv—O1—CE1^xii	109.471 (5)
O1^xvi—CE1—O1^xvii	109.471 (5)	CE1^iv—O1—GD1	109.471 (5)
O1^xvi—CE1—O1^xviii	109.471 (10)	CE1^iv—O1—GD1^iv	0.0
O1^xvi—CE1—O1^xix	70.529 (5)	CE1^iv—O1—GD1^viii	109.471 (10)
O1^xvii—CE1—O1^xviii	109.471 (5)	CE1^iv—O1—GD1^xii	109.471 (5)
O1^xvii—CE1—O1^xix	70.529 (10)	CE1^iv—O1—HO1	109.471 (5)
O1^xviii—CE1—O1^xix	70.529 (5)	CE1^iv—O1—HO1^iv	0.0
O1—GD1—O1^xiii	70.529 (10)	CE1^iv—O1—HO1^viii	109.471 (10)
O1—GD1—O1^xiv	70.529 (5)	CE1^iv—O1—HO1^xii	109.471 (5)
O1—GD1—O1^xv	70.529 (5)	CE1^viii—O1—CE1^xii	109.471 (5)
O1—GD1—O1^xvi	109.471 (5)	CE1^viii—O1—GD1	109.471 (5)
O1—GD1—O1^xvii	109.471 (10)	CE1^viii—O1—GD1^iv	109.471 (10)
O1—GD1—O1^xviii	109.471 (5)	CE1^viii—O1—GD1^viii	0.0
O1—GD1—O1^xix	180.0	CE1^viii—O1—GD1^xii	109.471 (5)
O1^xiii—GD1—O1^xiv	109.471 (5)	CE1^viii—O1—HO1	109.471 (5)
O1^xiii—GD1—O1^xv	109.471 (5)	CE1^viii—O1—HO1^iv	109.471 (10)
O1^xiii—GD1—O1^xvi	70.529 (5)	CE1^viii—O1—HO1^viii	0.0
O1^xiii—GD1—O1^xvii	180.0	CE1^viii—O1—HO1^xii	109.471 (5)
O1^xiii—GD1—O1^xviii	70.529 (5)	CE1^xii—O1—GD1	109.471 (10)
O1^xiii—GD1—O1^xix	109.471 (10)	CE1^xii—O1—GD1^iv	109.471 (5)
O1^xiv—GD1—O1^xv	109.471 (10)	CE1^xii—O1—GD1^viii	109.471 (5)
O1^xiv—GD1—O1^xvi	70.529 (10)	CE1^xii—O1—GD1^xii	0.0
O1^xiv—GD1—O1^xvii	70.529 (5)	CE1^xii—O1—HO1	109.471 (10)
O1^xiv—GD1—O1^xviii	180.0	CE1^xii—O1—HO1^iv	109.471 (5)
O1^xiv—GD1—O1^xix	109.471 (5)	CE1^xii—O1—HO1^viii	109.471 (5)
O1^xv—GD1—O1^xvi	180.0	CE1^xii—O1—HO1^xii	0.0
O1^xv—GD1—O1^xvii	70.529 (5)	GD1—O1—GD1^iv	109.471 (5)
O1^xv—GD1—O1^xviii	70.529 (10)	GD1—O1—GD1^viii	109.471 (5)
O1^xv—GD1—O1^xix	109.471 (5)	GD1—O1—GD1^xii	109.471 (10)
O1^xvi—GD1—O1^xvii	109.471 (5)	GD1—O1—HO1	0.0
O1^xvi—GD1—O1^xviii	109.471 (10)	GD1—O1—HO1^iv	109.471 (5)
O1^xvi—GD1—O1^xix	70.529 (5)	GD1—O1—HO1^viii	109.471 (5)
O1^xvii—GD1—O1^xviii	109.471 (5)	GD1—O1—HO1^xii	109.471 (10)
O1^xvii—GD1—O1^xix	70.529 (10)	GD1^iv—O1—GD1^viii	109.471 (10)
O1^xviii—GD1—O1^xix	70.529 (5)	GD1^iv—O1—GD1^xii	109.471 (5)
O1—HO1—O1^xiii	70.529 (10)	GD1^iv—O1—HO1	109.471 (5)
O1—HO1—O1^xiv	70.529 (5)	GD1^iv—O1—HO1^iv	0.0
O1—HO1—O1^xv	70.529 (5)	GD1^iv—O1—HO1^viii	109.471 (10)
O1—HO1—O1^xvi	109.471 (5)	GD1^iv—O1—HO1^xii	109.471 (5)
O1—HO1—O1^xvii	109.471 (10)	GD1^viii—O1—GD1^xii	109.471 (5)
O1—HO1—O1^xviii	109.471 (5)	GD1^viii—O1—HO1	109.471 (5)
O1—HO1—O1^xix	180.0	GD1^viii—O1—HO1^iv	109.471 (10)
O1^xiii—HO1—O1^xiv	109.471 (5)	GD1^viii—O1—HO1^viii	0.0
O1^xiii—HO1—O1^xv	109.471 (5)	GD1^viii—O1—HO1^xii	109.471 (5)
O1^xiii—HO1—O1^xvi	70.529 (5)	GD1^xii—O1—HO1	109.471 (10)
O1^xiii—HO1—O1^xvii	180.0	GD1^xii—O1—HO1^iv	109.471 (5)
O1^xiii—HO1—O1^xviii	70.529 (5)	GD1^xii—O1—HO1^viii	109.471 (5)
O1^xiii—HO1—O1^xix	109.471 (10)	GD1^xii—O1—HO1^xii	0.0
O1^xiv—HO1—O1^xv	109.471 (10)	HO1—O1—HO1^iv	109.471 (5)
O1^xiv—HO1—O1^xvi	70.529 (10)	HO1—O1—HO1^viii	109.471 (5)
O1^xiv—HO1—O1^xvii	70.529 (5)	HO1—O1—HO1^xii	109.471 (10)
O1^xiv—HO1—O1^xviii	180.0	HO1^iv—O1—HO1^viii	109.471 (10)
O1^xiv—HO1—O1^xix	109.471 (5)	HO1^iv—O1—HO1^xii	109.471 (5)
O1^xv—HO1—O1^xvi	180.0	HO1^viii—O1—HO1^xii	109.471 (5)

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