论文部分内容阅读
通过X射线衍射及磁测量手段研究了Y2Fe15Al2化合物的结构及磁学性质。结果表明:Y2Fe15Al2化合物具有六角相的Th2Ni17型结构。X射线热膨胀测量表明:在363～466 K的温度范围内,Y2Fe15Al2化合物出现负热膨胀现象,其平均热膨胀系数为α= -2.45 × 10-5/K。通过比较实际测量得到的晶格参数和外延计算得到的顺磁态的晶格参数之间的差别,在282～466 K的温度区间内计算了化合物的本征磁致伸缩系数。结果表明:化合物的本征体磁致伸缩随着温度的升高从282 K时的 11.3 × 10-3下降到466 K时的接近于零;化合物沿 c 轴方向和基面内的本征线磁致伸缩都随着温度的升高而下降,并且在400 K以下沿c轴方向的本征线磁致伸缩比基面内的本征线磁致伸缩大,这表明沿c轴方向的磁弹耦合强度高于基面内的磁弹耦合强度。
The structure and magnetic properties of Y2Fe15Al2 were investigated by X-ray diffraction and magnetic measurements. The results show that the Y2Fe15Al2 compound has a hexagonal Th2Ni17 structure. X-ray thermal expansion measurements show that the Y2Fe15Al2 compounds exhibit negative thermal expansion at a temperature range of 363 to 466 K with an average coefficient of thermal expansion of -2.45 × 10 -5 / K. The intrinsic magnetostriction coefficient of the compounds was calculated in the temperature range of 282 ~ 466 K by comparing the difference between the actually measured lattice parameters and the paramagnetic lattice parameters calculated by epitaxy. The results show that the magnetostriction of the compounds is close to zero with the increase of the temperature from 11.3 × 10-3 to 466 K at 282 K, and the compound along the c axis and the intrinsic line Magnetostrictives both decrease with increasing temperature, and the magnetostriction along the c-axis below 400 K is larger than the intrinsic magnetostriction within the basal plane, indicating that magnetism along the c-axis The elastic coupling strength is higher than the magnetic elastic coupling strength in the basal plane.