论文标题
AL8.5-XFE23GE12.5+X中铁磁和抗铁磁状态之间的竞争（0 <= x <= 3）
Competition between ferromagnetic and antiferromagnetic states in Al8.5-xFe23Ge12.5+x (0<=x<=3)
论文作者
论文摘要
通过X射线衍射测量，金属化检查和磁电阻率测量值研究了多晶AL7+XFE23GE14-X-type Orthorhombic AL8.5-XFE23GE12.5+X（0 <= X <= 3）化合物。晶格参数显示各向异性X依赖性，反映了相当复杂的晶体结构的较低对称性。在X = 0样品中，在255 K的Curie温度TC处发生铁磁（FM）过渡，随着X的增加而系统地减少，在X = 2.5时消失，其中实现了抗铁磁（AFM）基态。 Neel温度TN似乎以X> = 1出现，并在X = 3时生长至143 K，并增量为X。在x的中间范围（1 <= x <= 2）的中间范围内，AFM相变的FM出现在TC以下。在AFM相中，电阻率RHO显示出Fermi表面的不稳定性，其特征是Rho在大约TN以下的上升。 FM和AFM国家之间的竞争将归因于Fe-Fe键长的各向异性X依赖性。
Polycrystalline Al7+xFe23Ge14-x-type orthorhombic Al8.5-xFe23Ge12.5+x (0<=x<=3) compounds were studied by X-ray diffraction measurement, metallographic examination, and magnetization and electrical resistivity measurements. The lattice parameters show anisotropic x dependences, reflecting a lower symmetry of rather complex crystal structure. In the x=0 sample, a ferromagnetic (FM) transition occurs at the Curie temperature TC of 255 K, which is systematically reduced with increasing x and disappears at x=2.5 where an antiferromagnetic (AFM) ground state is realized. The Neel temperature TN seems to appear at x>=1, and grows to 143 K at x=3 with the increment of x. In the intermediate range of x (1<=x<=2), a FM to AFM phase transition occurs below TC. In the AFM phase, the electrical resistivity rho shows a Fermi surface instability characterized by the upturn of rho below approximately TN. The competition between the FM and AFM states would be ascribed to the anisotropic x dependences of Fe-Fe bond lengths.
