Structural Characterization And Magnetic Properties Of RIn_3-xFe_x?R=Pr,Nd,Gd,Ho? Compounds

The magneto-electronic material as a novel functional material is playing an important role in IT industry.It shows both of magnetic and semiconducting characteristics by the coupling between charges and spins.In this study,a novel magneto-electronic compound with a normal composition of RIn3-xFex is designed by doping small amount of Fe into the rare earth-indium semiconductor,magnetic ordered states is expected to form by the coupling interaction between Fe and Fe or Fe and R.The starting alloys with the nominal compositions of Rn3-xFex were prepared using arc-melting in an atmosphere of argon gas.The planar indices were determined with a TREOR program.The lattice parameters and unit cell volumes were determined.The crystal structures and atomic occupations were determined using a Rietveld structural refinement technology.The VSM was used to investigate the magnetic properties.According to the analysis to the measurments,the refined results reveal that the main phase of RIn3-xFex crystallizes cubic structure with a group space of Pm-3m and Z=1.The rare earth atoms occupy the 1a(0,0,0)position,indium atoms are at the 3c(0,0.5,0.5)sites.The doping element iron prefers to occupy the 3c crystal position.With the increase of the content of Fe,lattice parameter a and cell volumn V appear to decrease.This could be attributed to the effect of atomic radius for the doping element Fe smaller than In.The second phase induced by Fe doping into RIn3 has been observed in RIn3-xFex,and it has been determined to be elemental In.The VSM results show the magnetic properties of RIn3-xFex are very sensitive to Fe content.Fe doping into RIn3 induces the formation of ferromagnetic phase at room temperature(300K).With increasing Fe content,the magnetic phases exhibit a transition from paramagnetic to a mixture of ferromagnetic and paramagnetic.The susceptibility ?P and Ms increase with increasing Fe contents in RIn3-xFex.The main phase of RIn2,9Fe0.1 crystallize in cubic structure with space group of Pm-3m and Z=1.The lattice parameters and unit cell volumes decrease with atomic number of R increasing.This results in the shrinkage of the atomic radius with atomic number of R increasing.