【摘要】 制备了伪双元合金Hf0.82Ta0.18Fe2。X射线衍射表明,合金为C14型Laves相结构,晶格常数为a=4.92133(3),c=8.0488(1)。在温度20K～380K范围内测量了穆斯堡尔谱。表明合金随温度存在两个磁相变点,一个从顺磁态(PM)到反铁磁态(AFM),相变温度为330K,另一个从反铁磁(AFM)到铁磁态(FM),相变温度约为180K。在AFM-FM相变点,6h位Fe原子自旋方向发生翻转,从沿c方向转向ab平面。相应地,2a位的Fe原子,在AFM态为顺磁性,经过该相变后,相应地呈现铁磁性排列。更多还原

【Abstract】 The pseudobinary alloy Hf0.82Ta0.18Fe2 was prepared by arc melting and annealing technique. X-ray powder diffraction indicated a C14-type Laves phase structure with the crystal parameters a = 4.92133(3) and c = 8.0488(1). The Mssbauer spectra were measured at different temperatures between 20 K and 380 K,and showed two magnetic phase transitions,one from paramagnetic state to antiferromagnetic state at about 330 K and the other from antiferromagnetic state to ferromagnetic state at about 180 K. The latter transition indicated a spin-reorientation for 6h site Fe atoms,thus,the Fe atom spin at 6h turn to ab plane from c axis. However,the Fe atoms at 2a also showed a magnetic moment in ferromagnetic state.更多还原