中文摘要：

从多铁材料出发，介绍了三角反铁磁多铁材料ACrO2（A=Li，Na，K，Ag或Cu）的最新研究进展．这类多铁材料的磁性和铁电性存在很强的耦合和相互调控效应，铁电性来源于非共线螺旋自旋序，具有丰富的物理内涵，在自旋电子学等领域有着广阔的应用前景．基于密度泛函理论（DFT）的投影扩充波（PAW）方法，在广义梯度近似（GGA）下，对AgCrO2的磁结构和磁电性质进行了研究．共线磁结构计算结果表明，AgCrO2材料具有条纹反铁磁基态．态密度分析显示，Cr^3＋对体系的物理性质起决定性作用．通过非共线磁性结构计算，分别给出了平行于（110）而（11^-0）面内120°自旋构型．AgCrO2与（11^-0）具有很强的层内耦合作用，而层间耦合作用非常微弱，是典型二维三角格子Heisenberg材料．

英文摘要：

Beginning with the multiferroic material, recent advances in triangular antiferromagnets ACrO2 （A=Li, Na, K, Ag, or Cu） are introduced. The ferroelectricity of compounds ACrO2 is driven by spiral-spin ordering. Due to the combination of magnetic and dielectric properties, with eventual cross-coupling between these properties, such muhiferroics combine very rich and interesting fundamental physics problems with a technologically appealing po- tential for applications in the general area of spintronic. The magnetic structure, electronic structure and magnetism of AgCrO2 have been studied by using the density function theory （DFT） with the generalized gradient approximation （GGA） using the projected augmented wave （PAW） method. Based on the collinear magnetic structure calculation, the magnetic ground state is found to be striped antiferromagnetic. The density of states indicates that the physics properties of AgCrO2 are determined by Cr^3＋. By performing non-collinear magnetic structure calculations, the 120° spin structure within the spiral plane parallel to （110） or （11^0） plane are given, respectively. AgCrO2 is expected to be a good two-dimensional triangular lattice Heisenberg material with strong interlayer coupling and very weak interlayer interaction.