scholarly journals Layered (Cu,Fe) oxides of double perovskite structure: Correlation between structural and magnetic-property changes inBaY(Cu0.5Fe0.5)2O5+δupon high-pressure heat treatment

1998 ◽  
Vol 58 (6) ◽  
pp. 3371-3376 ◽  
Author(s):  
M. Nagase ◽  
J. Lindén ◽  
J. Miettinen ◽  
M. Karppinen ◽  
H. Yamauchi
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Magnetic Property ◽  
Perovskite Structure ◽  
Double Perovskite ◽  
Fe Oxides ◽  
Structure Correlation ◽  
Property Changes

scholarly journals Multiple magnetic interactions in ordered perovskite-structure oxides

2014 ◽  
Vol 70 (a1) ◽  
pp. C981-C981
Author(s):  
Yuichi Shimakawa
Keyword(s):  
High Pressure ◽  
Transition Metal ◽  
Transition Metal Oxides ◽  
Perovskite Structure ◽  
Double Perovskite ◽  
Transition Metal Ions ◽  
Magnetic Interactions ◽  
Spin Frustration ◽  
Tetrahedral Framework ◽  
Dependent Transport

Cation ordering in transition-metal oxides often drastically modifies their properties. We focus on A-and-B-site-ordered quadruple perovskite-structure oxides AA'3B2B'2O12, in which transition-metal ions are included at the A', B, and B' sites in an ordered manner. In such compounds A'-A', A'-B, A'-B', and B-B' interactions compete with each other and play important role in giving rise to unusual properties. The A-and-B-site-ordered quadruple perovskite CaCu3Fe2Sb2O12with magnetic Fe3+at the B site and nonmagnetic Sb5+at the B' site was successfully synthesized under a high-pressure and high-temperature condition. The B-site Fe3+spin sublattice adapts a tetrahedral framework and the Fe3+-Fe3+antiferromagnetic interaction causes geometrical spin frustration as seen in the double perovskite Ca2FeSbO6. With the introduction of Cu2+into the A' site, the frustration is relieved by strong antiferromagnetic A'(Cu2+)-B(Fe3+) interaction, leading to a ferrimagnetic ordering below 160 K. When B'-site Sb5+was replaced with Re5+, another A-and-B-site-ordered quadruple perovskite CaCu3Fe2Re2O12was synthesized by a high-pressure technique. The compound contains magnetic Fe3+at the B site and Re5+at the B' sites, and strong antiferromagnetic A'(Cu2+)-B'(Re5+) interaction overcomes the A'(Cu2+)-B(Fe3+) interaction, leading to a ferrimagnetism with the ferromagnetic A'(Cu2+)-B(Fe3+) spin arrangement below 550 K. More importantly, the electronic structure of CaCu3Fe2Re2O12is half metallic and the compound shows large magnetoresistance by the spin-dependent transport.

Comparison of Ricotta cheese made by high pressure treatment with that produced by heat treatment of sweet whey

2002 ◽  
Vol 22 (5) ◽  
pp. 601-615 ◽  
Author(s):  
Souhail Besbes ◽  
Christophe Blecker ◽  
Hamadi Attia ◽  
Carine Massaux ◽  
Claude Deroanne
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Pressure Treatment ◽  
High Pressure Treatment ◽  
Sweet Whey
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