Spacio-temporal Correlatins and Ground States in Strongly Frustrated Systems

强受挫系统中的时空相关性和基态

基本信息

批准号：
09640427
负责人：
MEKATA Mamoru
金额：
$ 1.79万
依托单位：
Fukui University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640427/
关键词：
Frustration Ground state Triangular Lattice Kagome Lattice Tetrahedron Lattice Singlet State Quantum Effect 四面対格子

项目摘要

The present study was performed to reveal the spacio-temporal correlations and quantum effect in strongly competing systems due to geometrical frustration by means of magnetic measurements on model compounds and computer simulation. The studied model compounds include CsNi(Fe)Cl_3 and BaVS_3 with the triangular lattice of magnetic chains, delafossite type compounds CuFe_<0.95>Al_<0.05>O_2 and A gNiO_2 with the rhombohedrally stacked triangular lattice, SrCr_8Ga_4O_<19> with the Kagome lattice, Cu_9X_2(cpa)_6 nH_2O (X=F,Cl, Br) with the triangulated Kagome lattice, beta-Mn with the corner sharing triangle lattice in three dimension and Y(Sc)Mn_2 with the corner sharing tetrahedron lattice.The observed ground states of these model compounds may be divided in several groups. CsNi(Fe)C1_3 and CuFe_<0.95> Al_<0.05>O_2 exhibit long range orders due to magnetic interaction between further neighbor spins than the nearest but have complicated magnetic structures due to spin frustration. Frustration gives rize to an orbital ordering in BayS3 with orbital degeneracy. The others have ground states with frozen spins which are different from conventional spin glasses in negative Weiss temperature of large magnitude. Each spinfrozen state exhibits individual features. The reciprocal magnetic susceptibility of SrCr_8Ga_4O_<19> and Cu_6X2(cpa)_3 nH_2O change the temperature gradient at much higher temperature than the spin freezing indicating singlet formation due to quantum effect. The spin freezing found in beta-Mn and Y(Sc)Mn_2 was attributed to the spin freezing of moments induced by lattice defects and it was concluded that the majority spins in these compounds are in spin liquid state. The conditions which determine the classical spin freezing and the quantum freezing are still future problem.

进行本研究以揭示由于模型化合物和计算机仿真的磁测量的几何挫折，因此揭示了强烈竞争系统中的时空相关性和量子效应。研究的模型化合物包括CSNI（Fe）CL_3和BAVS_3，带有磁链的三角形晶格，Delafossite类型化合物CUFE_ <0.95> al_ <0.05> o_2和gnio_2 and gnio_2与rhombohedrally堆叠的三角形三角形lattice，srcrcrcrcr__8ga _4.8Ga8GA <199 Cu_9x_2（CPA）_6 NH_2O（X = F，Cl，Br）带有三角形的Kagome Lattice，beta-mn的beta-mn，拐角在三个维度上共享三角晶格，y（sc）Mn_2与拐角处的Tetrahedron lattice共享这些模型复合组的tetrahedron lattice。 CSNI（Fe）C1_3和CUFE_ <0.95> Al_ <0.05> O_2由于在更近的邻居旋转之间的磁相互作用而与最近的磁性相互作用相比，由于旋转挫败感而具有复杂的磁性结构。挫败感给轨道变性的bays3中的轨道订购带来了损失。其他的具有冷冻旋转的基态，其与传统的自旋玻璃不同，在较大的Weiss温度下。每个旋转状态都表现出个人特征。 SRCR_8GA_4O__ <19>和CU_6X2（CPA）_3 NH_2O的相互磁敏感性在温度较高的温度下改变温度梯度比指示量子效应所导致的单线形成的温度梯度更高。在β-MN和Y（SC）MN_2中发现的自旋冷冻归因于晶格缺陷引起的矩旋转的旋转冻结，得出的结论是，这些化合物中的大多数旋转处于自旋液态状态。确定经典自旋冷冻和量子冷冻的条件仍然是将来的问题。