作者: D Serrate , J M De Teresa , M R Ibarra
DOI: 10.1088/0953-8984/19/2/023201
关键词: Tunnel junction 、 Exchange interaction 、 Condensed matter physics 、 Spin polarization 、 Coercivity 、 Ionic radius 、 Magnetoresistance 、 Chemistry 、 Ferromagnetism 、 Fermi level
摘要: We review the structural, magnetic and transport properties of double perovskites (A2BB'O6) with ferromagnetism above room temperature. Ferromagnetism in these compounds is explained by an indirect B?O?B'?O?B exchange interaction mediated itinerant electrons. first focus on BB' =?FeMo-based perovskites, Sr2FeMoO6 (TC = 420?K) being most studied compound. These show metallic behaviour low coercivity. Afterwards, we will B' Re compounds, where significant orbital moment plays a crucial role properties, for example large coercivity magnetostructural coupling. More specifically, discuss A2FeReO6 series, maximum TC 520?K Ca2FeReO6, which shows tendency to semiconducting behaviour. Finally, describe Sr2(Fe1?xCrx)ReO6 625?K Sr2CrReO6, highest oxide compound without Fe. This metallic. impact materials spin electronics light their high polarization at Fermi level metallicity. In particular, intergrain magnetoresistance effect observed polycrystalline samples possible implementation as electrodes tunnel junctions.