Large Intragrain Magnetoresistance above Room Temperature in the Double Perovskite Ba2FeMoO6
Large Intragrain Magnetoresistance above Room Temperature in the Double Perovskite Ba2FeMoO6
复制标题
双钙钛矿 Ba2FeMoO6 在室温以上具有大的晶内磁阻
DOI：
10.1006/jssc.1998.8129
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发表时间：
1999
影响因子：
5.4
通讯作者：
M. Hervieu
中科院分区：
文献类型：
--
作者：
A. Maignan;B. Raveau;C. Martin;M. Hervieu
首次显示了有序双钙钛矿 Ba2FeMo6 中的大晶粒内磁阻 (MR)。后者出现在 TC(340 K) 附近，即高于室温。这种效应源自基于局域高自旋 3d5Fe3+ 和流动 4d1Mo5+ 物质的反铁磁耦合的双交换机制。除了这种块状 MR 之外，由于晶界效应，在较低温度 (T<250 K) 下也观察到了低场隧道 MR，其 MR 值与之前在 Sr2FeMoO6 中观察到的值相当。晶粒内和晶间磁阻这两种效应的共存可能会扩展到该双钙钛矿家族的所有成员，这表明通过调整此类钙钛矿固溶体的 Tc 来优化 MR 在室温低磁场下工作的可能性。
Large intragrain magnetoresistance (MR) in the ordered double perovskite, Ba2FeMo6, is shown for the first time. The latter appears nearTC(340 K), i.e., above room temperature. This effect originates from a double-exchange-like mechanism, based on antiferromagnetic coupling of localized high spin 3d5Fe3+, and itinerant 4d1Mo5+species. Besides this bulk MR, low field tunneling MR at lower temperatures (T<250 K), due to grain boundary effects, is also observed with large values of MR comparable to those previously observed for Sr2FeMoO6. Such a coexistence of both effects, intragrain and intergrain magnetoresistance, might extend to all members of this double perovskite family, suggesting the possibility of optimizing the MR for working at room temperature in a low magnetic field, by tuning theTCof solid solutions of such perovskites.