Structural, electronic, and magneto-optical properties of YVO3
Structural, electronic, and magneto-optical properties of YVO3
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YVO3 的结构、电子和磁光特性
DOI：
10.1103/physrevb.69.075110
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发表时间：
2003
影响因子：
3.7
通讯作者：
G. Sawatzky
中科院分区：
文献类型：
--
作者：
A. Tsvetkov;F. Mena;P. Loosdrecht;D. van der Marel;Y. Ren;A. Nugroho;A. Menovsky;I. Elfimov;G. Sawatzky
研究了YVO3单晶在远红外、可见光和紫外区域的光学和磁光性质。观察到 75 K 和 200 K 时的两个结构相变，并分别确定为一级和二级结构相变。该晶格在 200 K 以上和 75 K 以下均具有斜方 Pbnm 对称性，并且被发现为二聚单斜晶 Pb11 或三斜晶 P1 。我们将 YVO3 确定为光学间隙为 1.6 eV 的莫特-哈伯德绝缘体。可见光谱显示 1.8、2.4 和 3.3 eV 处的三个 d 带激发，然后是约 4 eV 处的电荷转移跃迁。观察到的结构与 LSDA1U 能带结构计算结果非常一致。通过考虑配体场，我们将这些带分配给 4 A2g 、 2 Eg1 2 T1g 和 2 T2g 态的跃迁。这些能带对温度的强烈依赖性与轨道有序的形成一致。尽管每个钒的净磁矩很小，为 0.01m B，但在所有三个 d 带中都观察到了 0.01° 量级的克尔效应。
Optical and magneto-optical properties of YVO3 single crystal were studied in the far-infrared, visible, and ultraviolet regions. Two structural phase transitions at 75 K and 200 K were observed and established to be of first and second order, respectively. The lattice has an orthorhombic Pbnm symmetry both above 200 K as well as below 75 K and is found to be either dimerized monoclinic Pb11 or triclinic P1 ¯in between. We identify YVO3 as a Mott-Hubbard insulator with an optical gap of 1.6 eV. The visible spectrum shows three d-band excitations at 1.8, 2.4, and 3.3 eV, followed by charge-transfer transitions at about 4 eV. The observed structure is in good agreement with LSDA1U band structure calculations. By using ligand field considerations, we assigned these bands to the transitions to the 4 A2g , 2 Eg1 2 T1g , and 2 T2g states. The strong temperature dependence of these bands is in agreement with the formation of orbital order. Despite the small net magnetic moment of 0.01m B per vanadium, a Kerr effect of the order of 0.01° was observed for all three d bands in the