Abstract
From d.c. magnetization data obtained between 0.45 and 13 K we derive the bare Curie temperature, the temperature dependence of the paramagnetic susceptibility, and the coefficients of the higher order terms in the Landau expansion of the magnetic free energy for ErRh4B4. We find the unexpected result that the fourth order term is small or zero. Consequently the sixth order term plays the dominant role in stabilizing the magnetic phase.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1041-1044 |
| Number of pages | 4 |
| Journal | Solid State Communications |
| Volume | 39 |
| Issue number | 10 |
| DOIs | |
| State | Published - Sep 1981 |
Bibliographical note
Funding Information:The primitive tetragonal compound ErRh454 has attracted widespread attention because of its unusual properties.1-5 In zero external magnetic field, ErRh4B4 exhibits a superconducting transition at 8.7 K, but around 0.9 K the compound becomes normal close to the temperature at which long range magnetic order sets in. The theoretical analysis6-8 of this unusual behavior often begins with a Ginzburg-Landau type expansion of the free energy in the superconducting and magnetic order parameters. The behavior predicted by such theories depends sensitively on the values assumed for the various coefficients in these expansions.6 In this paper we discuss the derivation of the Ginzburg-Landau coefficients describing the magnetic behavior from experimental magnetization data. Subject to certain assumptions about *Work supported by the U.S. Department of Energy. **Research at UW-Milwaukee supported by the U.S. Air Force Office of Scientific Research under Grant No. AFOSR 81-0002. +Research at La Jolla sponsored by the National Science Foundation under Grant No. NSF/DMR 77-08469. ++Present Address: Corporate Research Laboratories, Exxon Research and Engineering co., Linden, New Jersey 07036.