不同制备工艺对多晶双钙钛矿Sr2FeMoO6室温磁电阻效应的影响

研究了固相反应法和溶胶-凝胶自燃法制备多晶Sr2FeMoO6块体样品的室温磁电阻效应,发现溶胶-凝胶自燃法制备的样品与固相反应法相比,室温磁电阻效应由2.9%上升到13.8%,增幅达3.76倍。溶胶-凝胶自燃法制备的前驱粉末为超微粉体,在烧结时能形成优异的晶界质量,需要的烧结温度低,结晶粒度小,晶界数目增多,使磁电阻增强;低的烧结温度易生成SrMoO4,加强绝缘势垒,因此具有好的磁电阻效应。

Effect of Different Preparing Processes on Room Temperature MR of Double Perovskite Sr2FeMoO6 Polycrystals

The room temperature MR effect of double perovskite Sr2FeMoO6 polycrystals prepared by the solid state reaction method and sol-gel self-spread combustion method were investigated. Compared with the solid state reaction process,the room temperature MR of the samples prepared by the sol-gel self-spread combustion method presented a very higher value of 13.8%,which increased 3.76-fold. The precursor samples prepared by sol-gel self-spread combustion method were super-micro particles,which could make the as-prepared samples with the lower sintered temperature,the smaller crystal and very more interfaces,which make the MR effect much stronger. The lower sintered temperature produced more SrMoO4,which could make the tunneling barrier stronger and benefit the MR effect.