Tuning the Mn valence state in new Ca 0.66 Mn 2-x Al x O 4 (x 0.4) oxides: impact on magnetic and redox properties.

Transcription

1 Electronic Supplementary Material (ESI) for Dalton Transactions. This journal is The Royal Society of Chemistry 206 SUPPLEMENTARY INFORMATIONS Tuning the Mn valence state in new Ca 0.66 Mn 2-x Al x O 4 (x 0.4) oxides: impact on magnetic and redox properties. Stéphanie Lesturgez,2, Graziella Goglio,2, François Weill,2, Olivier N Guyen,2, Olivier Toulemonde,2, Etienne Durand,2, Julien Hernandez 3, and Alain Demourgues*, Figure S: X-ray powder diffraction patterns range (counting time 2000s per step: ) of a) CaMn 3 O 6 =Ca 0.66 Mn 2 O 4 (monoclinic unit cell, SG: P2 /a) and b) Ca 0.66 Mn.6 Al 0.4 O 4 (orthorhombic unit cell, SG: Pnma) compounds. (hkl) indexations at low 2 angles are mentioned.

2 Figure S2: Rietveld refinement of X-ray powder diffraction patterns ( range, counting time 2000s per step: ) of CaMn 3 O 6 =Ca 0.66 Mn 2 O 4 compound. Calculated (in red), observed (in black), difference (in blue) patterns are represented. Bragg peaks (in green) are noted. Figure S3: X-ray powder diffraction patterns ( range, counting time 500s per step: 0.07 ) of Ca 0,66 Mn 2-x Al x O 4 (0<x 0.47) compounds. For x=0.47, the impurity (Brownmillerite-type phase) is marked with a star..

3 . Figure S4: Comparison of the temperature dependence of H/M susceptibility curve per mole of Mn for Ca 0.66 Mn 2 O 4 (in red), Ca 0,66 Mn,8 Al 0,2 O 4 (in black) and Ca 0,66 Mn,6 Al 0,4 O 4 (in blue) compounds (recorded with a magnetic field of 0 KOe).. Figure S5: Full Pattern Profile refinement of X-ray powder diffraction patterns ( range, counting time 60 s per step : 0.07 ) of the Ca 0.23 Mn 0.56 Al 0.4 O compound (rocksalt-type structure) obtained after reduction under Ar/H 2 5% of Ca 0.66 Mn.6 Al 0.4 O 4 oxide (TGA-Figures 9 and 2)

4 Figure S6 X-ray powder diffraction patterns ( range, counting time 500s per step: 0.07 ) of a) Ca 0,6 Mn,8 Al 0,2 O 4, b) Ca 0,66 Mn,8 Al 0,2 O 4 and c) Ca 0,7 Mn,8 Al 0,2 O 4 compounds. For the composition Ca 0,6 Mn,8 Al 0,2 O 4 the impurity considered as Brownmillerite-type (SG:Imma) phase (Ca 2 (Mn,Al) 2 O 5 ) is marked with a star..

5 Atom Wyckoff positions x y z Biso [Å 3 ] Occupancy Ca 4e (6) (6) (7).72(7) Ca2 4e (6) (6) 0.936(7) Mn 4e 0.057(5) 0.50(4) 0.469(7) Mn2 4e (6) 0.643(4) (8) Mn3 4e 0.087(6) (4) (7) Mn4 4e (6) (5) (7) Mn5 4e (6) 0.036(4) (8) Mn6 4e (5) (5) (8) O 4e 0.30() 0.642() 0.599() O2 4e 0.96() 0.6() 0.74(2) O3 4e 0.385(2) 0.977() 0.677(3) O4 4e 0.04() 0.472() 0.666(2) O5 4e 0.455() 0.986() 0.720(3) O6 4e 0.002() 0.69() 0.589(2) O7 4e 0.077(2) 0.90() 0.486(2) O8 4e 0.426(2) 0.47() 0.862(3) O9 4e 0.266() 0.644() 0.926(2) O0 4e 0.372() 0.99() 0.005(3) O 4e 0.465(2) 0.203() 0.072(3) O2 4e 0.07(2) 0.909() 0.89(3).72(7) 0.37(3) 0.37(3) 0.37(3) 0.37(3) 0.37(3) 0.37(3) Cell parameters SG: P2/a a(å) b(å) c(å) V(Å 3 ) ().33() () () CRp :20,2% CRwp:9,3 % RBragg=6,09% Table S : Atomic positions and unit cell unit parameters determined by Rietveld refinement ( Cu Kα, counting time 2000s per step: 0.008, Figure 4a) of powder X-Ray diffraction data of CaMn 3 O 6 oxide. The reliability factors CRp, CRpw and RBragg are mentioned.

6 Atom Wyckoff positions x y z Biso [Å 3 ] Occupancy Ca 4c (3) Mn 4c () (2) 3.79(8) (9) 0.323() 0.846() Al 4c () 0.39(9) 0.323() 0.54() Mn2 4c (2) () 0.323() 0.754() Al2 4c (2) () 0.323() () O 4c (5) 0.652(3).0(4) O2 4c (4) (3).0(4) O3 4c (5) 0.985(3).0(4) O4 4c 0.069(6) 0.949(3).0(4) Cell parameters SG: Pnma a(å) b(å) c(å) V(Å 3 ) (2) (9).2802(3) 285.2() CRp :5.7% CRwp:2.6 % RBragg 6.42 % Table S2a: Atomic positions and unit cell unit parameters determined by Rietveld refinement ( Cu Kα, counting time 2000s per step: 0.008, Figure 4a) of powder X-Ray diffraction data of Ca 0.66 Mn.6 Al 0.4 O 4 oxide. The reliability factors CRp, CRpw and RBragg are mentioned. Structural hypothesis: Al atoms distribution in two Mn/Mn2 sites.

7 Atom Wyckoff positions x y z Biso [Å 3 ] Occupancy Ca 4c (3) () 2.68(5) Mn 4c () 0.53(6) 0.34() 0.944() Mn2 4c 0.083() (6) 0.34() 0.856() Al2 4c 0.083() (6) 0.34() 0.44() Al 4c () 0.53(6) 0.34() 0.056() O 4c (3) 0.65(2) 0.36(2) O2 4c (2) (2) 0.36(2) O3 4c (3) 0.978(2) 0.36(2) O4 4c 0.070(4) 0.948(2) 0.36(2) Cell parameters SG: Pnma a(å) b(å) c(å) V(Å 3 ) (2) (4).288(2) (9) CRp :5.7% CRwp:2.9% RBragg 8.66% Table S2b: Atomic positions and unit cell parameters determined by Rietveld refinement ( Cu Kα, counting time 2000s per step: 0.008, Figure 4b) of powder X-Ray diffraction data of Ca 0.66 Mn.8 Al 0.2 O 4 oxide.the reliability factors CRp, CRpw and RBragg are mentioned. Structural hypothesis: Al atoms distribution in two Mn/Mn2 sites.

8 Atoms Mn2 Al2 O3.92(3) Mn2 Al2 O3.92(3) Mn2 Al2 O2.935(3) Mn2 Al2 O2.935(3) Mn2 Al2 O.964(5) Mn2 Al2 O2.976(4) <Mn2-O>.939(3) < > = Mn2-O-<Mn2 -O> / (3) Brown bond valence 3.70 Atoms Mn Al O4.909(4) Mn Al O4.909(4) Mn Al O.937(3) Atoms Ca O (5) Ca O (5) Ca O (5) Ca O (4) Ca O (4) Ca O 2.55(4) Ca O 2.55(4) Ca O (5) <Ca-O> < > = Ca-O-<Ca -O> / Brown bond valence 2.36 Mn Al O.937(3) Mn Al O4 2.25(3) Mn Al O (4) <Mn-O> 2.035(3) < > = Mn-O-<Mn -O> /6 0.53(3) Brown bond valence 3.0 Table S3a: Bond distances and valence determined from Table S (Rietveld refinement of powder X- Ray diffraction data of Ca 0.66 Mn.6 Al 0.4 O 4, ( Cu Kα, counting time 2000s per step: 0.008, Figure 4a) oxide. The average <Mn-O> and <Ca-O> bonds distances as well as the average of the difference between main distance and average distance are mentioned. Structural hypothesis: Al atoms distribution in two Mn/Mn2 sites.

9 Atoms Mn2 Al2 O3.903(2) Mn2 Al2 O3.903(2) Mn2 Al2 O2.94() Mn2 Al2 O2.94() Mn2 Al2 O.977(2) Mn2 Al2 O2.979(2) <Mn2-O>.940(2) < > = Mn2-O-<Mn2 -O> / (2) Brown bond valence 3.69 Atoms Mn Al O4.95(2) Mn Al O4.95(2) Mn Al O.932() Mn Al O.932() Atoms Ca O4 2.36(3) Ca O4 2.36(3) Ca O (3) Ca O (2) Ca O (2) Ca O 2.53(2) Ca O 2.53(2) Ca O (3) <Ca-O> < > = Ca-O-<Ca -O> / Brown bond valence 2.4 Mn Al O (2) Mn Al O3 2.33(3) <Mn-O> < > = Mn-O-<Mn -O> /6 Brown bond valence 2.038(2) 0.52(2) 3.09 Table S3b: Bond distances and valence determined from Table S2a (Rietveld refinement of powder X- Ray diffraction data of Ca 0.66 Mn.8 Al 0.2 O 4 ( Cu Kα, counting time 2000s per step: 0.008, Figure 4b) oxide. The average <Mn-O> and <Ca-O> bonds distances as well as the average of the difference between main distance and average distance are mentioned. Structural hypothesis: Al atoms distribution in two Mn/Mn2 sites.