Magnetic hyperfine field at s–p impurities on Laves phase compounds

Abstract

Recent experimental results for the magnetic hyperfine field B hf at the nuclei of s-p impurities such as 119 Sn in intermetallic Laves phases RM 2 (R = Gd, Tb, Dy, Ho, Er; M = Fe, Co) and 111 Cd in RCo 2 , the impurity occupying a R site indicate that the ratio B hf /µ 3d exhibits different behavior when one goes from RFe 2 to RCo 2 . In this work, we calculate these local moments and the magnetic hyperfine fields. In our model, B hf has two contributions: one arising from the R ions, and the other arising from magnetic 3d-elements; these separate contributions allow the identification of the origin of different behavior of the ratio mentioned above. For 111 Cd in RCo 2 we present also the contributions for B hf in the light rare earth Pr, Nd, Pm, Sm compounds. For the sake of comparison we apply also the model to 111 Cd diluted in RNi 2 . Our self-consistent magnetic hyperfine field results are in good agreement with those recent experimental data.

Theoretical study of the hyperfine field at Cu impurities diluted in an iron host

“…The magnetic moment formation at a Cu impurity diluted in Fe arises from the following effects: i) the charge difference between Fe and the impurity produces an electrostatic potential which the Fe conduction electron gas will shield; ii) a magnetic field produced by the d Fe band that acts in the impurity through its Fe neighbors [3,5] * alexandre.oliveira@ifrj.edu.br † cmch@cbpf.br and also in the whole host. Both contributions act differently on the impurity density of up and down spins thus producing a polarized conduction band and a magnetization m 0 = n 0↑ − n 0↓ both in the impurity and in the host as well.…”

Role of the electronic structure in the morphotropic phase boundary of TbxDy1−xCo2 studied by first-principle calculation

“…With the more results via experimental progress, the theoretical analysis made it possible to understand systematically the influence of the electronic structure on the magnetic properties 6 . A lot of researches [7][8][9][10] have been contributed on the theoretical and experimental investigation of RFe 2 , RCo 2 and RNi 2 . A debate on the phase transition, if is the spinreorientation transition also a border separating different crystal symmetries, has been continued for recent decades.…”