Susceptibility of dilutely doped CrFe alloys

Autor: V. Yu. Galkin, W.A. Ortiz, Randy Scott Fishman
Rok vydání: 1998
Předmět:
Zdroj: Journal of Physics: Condensed Matter. 10:6347-6366
ISSN: 1361-648X
0953-8984
DOI: 10.1088/0953-8984/10/28/015
Popis: For low dopant concentrations, Fe is the only impurity atom which exhibits Pauli paramagnetism below the Neel temperature of a Cr host. A series of measurements on and alloys reveal that the magnetization M is sensitive to the amplitude of the spin-density wave (SDW) below . The Fe moment also depends on the period of the SDW and is about 6% larger in the incommensurate than in the commensurate SDW state. Surprisingly, the differential susceptibility dM/dH peaks at the field , which is about 5 kOe for low temperatures and small V concentrations. While increases with the temperature, it decreases with the V and Fe concentrations. These observations may be explained by making the radical assumption that the rigidity of the Fe moment is broken by its interaction with the SDW. Whereas part of the Fe moment is bound to the SDW by the nesting free energy, the remainder experiences a weak effective field exerted by the surrounding SDW and by the ferromagnetically coupled, nearest-neighbour pairs of Fe atoms. The peak in dM/dH occurs when the external field H overcomes the antiferromagnetic field experienced by the single Fe atoms. This model explains the temperature and doping dependence of , as well as the difference between the Fe moments in the commensurate and incommensurate SDW hosts.
Databáze: OpenAIRE