Unusual magnetic properties of (Er1-xGdx)(5)Si-4 compounds

TitleUnusual magnetic properties of (Er1-xGdx)(5)Si-4 compounds
Publication TypeJournal Article
Year of Publication2008
AuthorsSingh NK, Pecharsky VK, Gschneidner KA
Journal TitlePhysical Review B
Date PublishedFeb
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberISI:000253764000056
Keywordsalloys, electrical-resistance, field, gd-5(si2ge2), HEAT-CAPACITY, intermetallic compounds, NEEL, rare-earth, refrigeration, temperature, transition

Magnetic and magnetocaloric properties of polycrystalline (Er1-xGdx)(5)Si-4 with x=0.1 and 0.25 have been studied. The temperature dependencies of the dc magnetization and ac susceptibility indicate two magnetic transitions: the high temperature transitions are antiferromagnetic in character, whereas the low temperature ones are of ferromagnetic nature. The isothermal magnetization of these compounds shows metamagneticlike transitions at 5 K and no saturation in fields up to 70 kOe. Time dependencies of the magnetization data below the Neel temperature exhibit unusually strong relaxation effects with logarithmic time dependence. The ac susceptibility data reveal that magnetic state of these compounds is distinctly different from spin glasses and the relaxation behavior seen in the magnetization data is a consequence of complex magnetic interactions. The existence of complex magnetic interactions leads to an easy formation of field induced short range ferromagnetic correlations in the paramagnetic state and greatly affects both the magnetic and magnetocaloric properties of these compounds.

Alternate JournalPhys. Rev. B