Single-Ion Anisotropy, Crystal-Field Effects, Spin Reorientation Transitions, and Spin Waves in <em>R</em><sub>2</sub>CuO<sub>4</sub> (<em>R</em>=Nd, Pr, and Sm)

Loading...
Thumbnail Image
Penn collection
Department of Physics Papers
Degree type
Discipline
Subject
Physics
Funder
Grant number
License
Copyright date
Distributor
Related resources
Author
Sachidanandam, Ravi
Aharony, Amnon
Entin-Wohlman, Ora
Contributor
Abstract

We report a detailed study of single-ion anisotropy and crystal-field effects in rare-earth cuprates R2CuO4 (R=Nd, Pr, and Sm). It is found that most of the magnetic properties are mainly due to the coupling between the copper and rare-earth magnetic subsystem which exhibits a large single-ion anisotropy. This anisotropy prefers ordering of rare-earth moments along [100] for R=Pr and Nd and along [001] for R=Sm. Combined with a pseudodipolar interaction arising from the anisotropy of the R-Cu exchange, we can explain the magnetic structures of these materials. The spin reorientation transitions in Nd2CuO4 can be explained in terms of a competition between various interplanar interactions which arises because of the rapid temperature dependence of the Nd moment below about 100 K. Finally we introduce a simple two-dimensional model for the Nd spin-wave spectrum. For zero wave vector, this model gives two optical modes involving Cu spins whose temperature-dependent energies agree with experimental results and an acoustic mode whose energy is predicted to be of order √(2k4Δ)≈5μeV, where k4 is the fourfold in-plane anisotropy constant and Δ is the Nd doublet splitting.

Advisor
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Publication date
1997-07-01
Journal title
Physical Review B
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
<p>At the time of publication, author Taner Yildirim was affiliated with the University of Maryland, College park, Maryland. Currently, he is a faculty member in the Department of Materials Science and Engineering at the University of Pennsylvania.</p>
Recommended citation
Collection