双层三角晶格反铁磁材料c-轴电阻性质的研究  

THE STUDY OF THE ANOMALOUS c-AXIS RESISTIVITY IN HOLE-DOPED BILAYER TRIANGULAR ANTIFERROMAGNETS

作　　者：关昕[1] 何敬[2] 梁颖[2] 

机构地区：[1]河北工业职业技术学院金属材料工程系,石家庄050091 [2]北京师范大学物理学系,北京100875

出　　处：《北京师范大学学报（自然科学版）》2009年第1期37-41,共5页Journal of Beijing Normal University(Natural Science)

摘　　要：由t-J模型出发，在feimion-spin理论框架下研究了空穴型掺杂双层三角晶格反铁磁材料c-轴的反常电阻行为．与面内电荷动力学不同的是，c-轴电荷输运与材料的种类有关．材料中CuO2平面之间是否有Cu-O链，对于材料的物理性质有很大的影响．对于层间存在Cu-O链的材料，c-轴方向的电荷动力学主要是由CuO2平面内holon的散射决定的，并且其c-轴电荷动力学与ab平面的电荷动力学在定性上是相似的；而对于层间不存在Cu-O链的材料，c-轴方向的电荷动力学是由CuO2平面内holon的散射和层间的无序效应共同决定的．此外，c-轴方向的电阻率比平面内的电阻率大3～4个数量级，这就意味着大部分的载流子被限制在了ab平面内．因此，双层三角晶格反铁磁材料正常态电荷动力学存在着很强的各向异性行为．由三角晶格反铁磁材料得到的结果与四方晶格相类似，但是由于三角晶格反铁磁材料自身存在的几何阻挫效应，使得二者的结果稍有差异．The c-axis resistivity of the hole doped bilayer triangle antiferromagnets within the t-J model based on the fermion-spin theory is studied. It is shown that the c-axis charge dynamics is dependent on the species of the building blocks between the CuO2 planes, that is, for the chain bilayer triangular antiferromagnet, the c-axis charge dynamics is mainly governed by the scattering from the in-plane fluctuation and its behavior is similar to the one of ab plane, while for the no-chain bilayer triangular antiferromagnet, it is dominated by the scattering from the in-plane fluctuation incorporating with the interlayer disorder. Besides, the quantity of c-axis resistivity is larger 3 -4 than the one of ab plane in the hole doped bilayer triangle antiferromagnets, that is, most carriers are confined to the ab plane. So the charge dynamics of the hole doped bilayer triangular lattice is highly anisotropic. The results are basically consistent with the square lattice materials but a little different in detail due to the inherent geometrical frustration in the triangular regime.

关 键 词：T-J模型 fermion-spin理论 双层三角晶格 电荷动力学 

分 类 号：O734[理学—晶体学] TM271.6[一般工业技术—材料科学与工程]