Magnetic-field-induced valence transition in rare-earth systems

Pramana

A Ramakanth²  G Gangadhar Reddy1²  S K Ghatak¹ 

[1] Department of Physics, Indian Institute of Technology, Kharagpur 721 302, India$$;Department of Physics, Kakatiya University, Warangal 506 009, India$$

关键词: Magnetic field;    valence transition;    rare-earths.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The magnetic-field-induced valence transition in rare-earth systems has been investigated using the periodic Anderson model supplemented by the Falicov–Kimball term. This model has been solved by first decoupling the Falicov–Kimball term as proposed by Khomskii and Koharjan and then taking the limit of infinite intra-site Coulomb repulsion. The valence transition both in the absence and in the presence of magnetic field as a function of temperature is studied. It has been found that the system makes transition from non-magnetic to magnetic state when the magnetic field increases beyond a critical value 𝐻c. The phase boundary defined in terms of reduced field 𝐻c(𝑇)/𝐻c(0) and reduced temperature 𝑇/𝑇v (𝑇v being the valence transition temperature in the absence of field) is almost independent of the position of the localized level. The results are in qualitative agreement with experimental observations in Yb- and Eu-compounds.

【 授权许可】

Unknown