Exchange interactions and anisotropic spin waves in bilayer manganites
Exchange interactions and anisotropic spin waves in bilayer manganites
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DOI：
10.1103/physrevb.67.092407
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发表时间：
2003-03-01
影响因子：
3.7
通讯作者：
Feiner, LF
中科院分区：
文献类型：
--
作者：
Oles, AM;Feiner, LF
我们提出了一个理论的磁相互作用的双层锰氧化物，锰氧化物的t-J模型的基础上，并表明铁磁相是一个各向异性的轨道液体无序状态。通过包括e（g）电子的相关性，我们解释了为什么层内交换耦合随着空穴掺杂x而增加。当x = 0.45时，La_（2 - 2）Sr_（1 + 2）Mn_2 O_7中的铁磁相转变为A型反铁磁相时，3 z（2）-r（2）轨道占有率下降，超交换项超过层间耦合的双交换项。
We present a theory of the magnetic interactions in the bilayer manganites, based upon the manganite t-J model, and show that the ferromagnetic phase is an anisotropic orbital liquid disordered state. By including the correlations of the e(g) electrons we explain why the intralayer exchange coupling increases with hole doping x. The transition from the ferromagnetic to A-type antiferromagnetic phase in La2-2xSr1+2xMn2O7 at xsimilar or equal to0.45 occurs when the occupancy of 3z(2)-r(2) orbitals drops and the superexchange term exceeds the double exchange in the interlayer coupling.