| 1. |
- Eriksson, A K, et al.
(författare)
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Effets of A-site substitution on the structure and magnetic properties of Bi0.15Sr0.85-yAeyCo1-xFexO3-o
- 2009
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Ingår i: Solid State Sciences. - : Elsevier BV. - 1293-2558 .- 1873-3085. ; 11:11, s. 1945-1954
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Tidskriftsartikel (refereegranskat)abstract
- The effects of partial substitution of Sr2+ by Ca2+ and Ba2+ on the A-site of oxygen-deficient perovskites, Bi(0.15)Sr(0.85-y)Ae(y)Co(1-x)FeO(3-delta), where y = 0.28 for Ae = Ba and y = 0.17 for Ae = Ca, and 0.0 <= x <= 1.0, have been investigated. The differing ionic size of the Ca2+ and Ba2+ cations influences both the crystal structure and the properties of the materials. The smaller Ca2+ cation favoured formation of an oxygen vacancy ordered perovskite superstructure (14/mmm, a = 2ap, c = 4a(p)), meanwhile the presence of the larger Ba2+ cation promoted a disordered simple cubic structure (Pm (3) over barm, a = ap) that was also found for all Fe containing samples, i.e. x >= 0.25. The samples were studied with PXRD, NPD, TGA, electron microscopy and magnetic susceptibility measurements. All as-prepared samples exhibited long range G-type antiferromagnetic ordering. The effect of oxygen annealing was dramatic for the Bi0.15Sr0.68Ca0.17Co1-xFexO3-delta series, with a disappearance of magnetic order for x >= 0.25 linked to increasing spin-glass properties. The oxygen content of the Bi0.15Sr0.57Ba0.28Co1-xFexO3-delta as-prepared materials was generally higher than their Ca substituted counterparts, and the long range antiferromagnetic order was more resistant to oxygen annealing.
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| 2. |
- Eriksson, Annika, 1975, et al.
(författare)
-
Effects of A-site substitution on the structure and magnetic properties of Bi(0.15)Sr(0.85-y)Ae(y)Co(1-x)Fe(x)O(3-delta) perovskites
- 2009
-
Ingår i: Solid State Sciences. - : Elsevier BV. - 1293-2558. ; 11:11, s. 1945-1954
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of partial substitution of Sr2+ by Ca2+ and Ba2+ on the A-site of oxygen-deficient perovskites, Bi(0.15)Sr(0.85-y)Ae(y)Co(1-x)FeO(3-delta), where y = 0.28 for Ae = Ba and y = 0.17 for Ae = Ca, and 0.0 = 0.25. The samples were studied with PXRD, NPD, TGA, electron microscopy and magnetic susceptibility measurements. All as-prepared samples exhibited long range G-type antiferromagnetic ordering. The effect of oxygen annealing was dramatic for the Bi0.15Sr0.68Ca0.17Co1-xFexO3-delta series, with a disappearance of magnetic order for x >= 0.25 linked to increasing spin-glass properties. The oxygen content of the Bi0.15Sr0.57Ba0.28Co1-xFexO3-delta as-prepared materials was generally higher than their Ca substituted counterparts, and the long range antiferromagnetic order was more resistant to oxygen annealing. (C) 2009 Elsevier Masson SAS. All rights reserved.
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| 3. |
- Eriksson, Annika K., et al.
(författare)
-
Effects of A-site substitution on the structure and magnetic properties of Bi0.15Sr0.85-yAeyCo1-xFexO3-? perovskites
- 2009
-
Ingår i: Solid State Sciences. - 1293-2558 .- 1873-3085. ; 11:11, s. 1945-1954
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of partial substitution of Sr2+ by Ca2+ and Ba2+ on the A-site of oxygen deficient perovskites, Bi0.15Sr0.85-yAeyCo1-xFexO3-?, where y = 0.29 for Ae = Ba and y = 0.17 for Ae = Ca, and 0.0 ? x ? 1.0, have been investigated. The differing ionic size of the Ca2+ and Ba2+ cations influences both the crystal structure and the properties of the materials. The smaller Ca2+ cation favoured formation of an oxygen vacancy ordered perovskite superstructure (I4/mmm, a = 2ap, c = 4ap), meanwhile the presence of the larger Ba2+ cation promoted a disordered simple cubic structure (Pm-3m, a = ap) that was also found for all Fe containing samples, i.e. x ? 0.25. The samples were studied with PXRD, NPD, TGA, HREM and magnetic susceptibility measurements. All as-prepared samples exhibited long range G-type antiferromagnetic ordering. The effect of oxygen annealing was dramatic for the Bi0.15Sr0.68Ca0.17Co1-xFexO3-? series with a disappearance of magnetic order for x ? 0.25 linked to increasing spin glass properties. The oxygen content of the Bi0.15Sr0.56Ba0.29Co1-xFexO3-? as-prepared materials was generally higher than their Ca substituted counterparts, and the long range antiferromagnetic order was more resistant to oxygen annealing.
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