The magnetic interactions between rare-earth and transition elements in the intermetallic compound

在最后一年，进行了剩余的测量。根据R(Fe,Mn)_<12> （R为稀土元素）的电子电阻，观察到CrMn合金的电子电阻因向反铁磁态转变而迅速增加，并用类似的方法解释了这一现象。假设Mn原子的反铁磁耦合，RMn_<12>的饱和磁化强度小于R^<3+>的期望值。这一事实表明R和Mn原子之间存在强相互作用。通过^<55>Mn NMR在T_C和T_N之间的温度范围内观察到R-Mn相互作用，其中T_C （<10K）为R原子的磁有序点，T_N （100K）为Mn原子的磁有序点。利用R(Fe,Mn)_<12>中^<57>Fe的穆斯堡尔效应，定量得到了Fe原子的位置偏好。8f站点最优惠，8i站点比较难。在较低铁密度下，估计铁的居群率（8j/8f）约为30%。另一个研究对象是研制强铁磁性物质。为了研究永磁体的基本性能，选择了铁磁化合物Gd_5Si_4作为起始物质，并进行了取代，以增加磁性各向异性。研究了R原子对磁性各向异性的影响。结果，没有发现居里温度更高的物质。而每个原子的磁矩比其他原子大。在低温下制造强永磁体是可能的。对R_2Co_<14>B的核磁共振研究表明了Co位对磁各向异性的贡献。根据这些结果，指出了形成强永磁体的条件。

In the final year, the remain measurements were carried out. According to the electronic resistances of R(Fe,Mn)_<12> where R is the rare earth element, the rapid increase due to the transition to the antiferromagnetic state was observed and explained by the similar method for CrMn alloy. The saturation magnetizations of RMn_<12> are smaller than the expected values for R^<3+> by assuming the antiferromagnetic coupling of Mn atoms. This fact suggests the existence of the strong interaction between R and Mn atoms. The R-Mn interaction was observed by ^<55>Mn NMR in the temperature range between T_C and T_N where T_C (<10K) is the magnetic ordering point of R atoms and T_N ( 100K) is that of Mn atoms. From the Mossbauer effect of ^<57>Fe in R(Fe,Mn)_<12>, The site preference of Fe atom was quantatively obtained. 8f-site is most preferential and 8i-site is hard. In the lower density of Fe , the population rate of Fe (8j/8f) is estimated to be about 30%.The another object of study is to develop strong ferromagnetic substances. In order to study the basic properties of permanent magnets, the ferromagnetic compound Gd_5Si_4 was selected as a start substance and substituted to increase the magnetic anisotropy. The contribution of R atom to the magnetic anisotropy was also investigated. As a result, the substance with higher Curie temperature was not found. While the magnetic moment per atom was larger than others. The strong permanent magnet is possible at low temperature. The NMR study of R_2Co_<14>B indicates the contribution to the magnetic anisotropy of Co sites. From these results the conditions of the possibility of the strong permanent magnet are pointed out.