Heat capacity and thermal expansion of the itinerant helimagnet MnSi

TitleHeat capacity and thermal expansion of the itinerant helimagnet MnSi
Publication TypeJournal Article
Year of Publication2008
AuthorsStishov SM, Petrova AE, Khasanov S, Panova GK, Shikov AA, Lashley JC, Wu D, Lograsso TA
Journal TitleJournal of Physics-Condensed Matter
Volume20
Pages235222
Date PublishedJun
Type of ArticleArticle
ISBN Number0953-8984
Accession NumberISI:000256172800024
Keywordsbehavior, MONOSILICIDES, order, phase-transitions, weak ferromagnetism
Abstract

The heat capacity and thermal expansion of a high quality single crystal of MnSi were measured at ambient pressure at zero and high magnetic fields. The calculated magnetic entropy change in the temperature range 0-30 K is less than 0.1R, a low value that emphasizes the itinerant nature of magnetism in MnSi. A linear temperature term dominates the thermal expansion coefficient in the range 30-150 K, which correlates with an enhancement of the linear electronic term in the heat capacity. A surprising similarity among the variations of the heat capacity, thermal expansion coefficient and temperature derivative of the resistivity is observed through the phase transition in MnSi. Specific forms of the heat capacity, thermal expansion coefficient and temperature derivative of resistivity at the phase transition to a helical magnetic state near 29 K are interpreted as the combination of sharp first-order features and broad peaks or shallow valleys of as yet unknown origin. The appearance of these broad satellites probably hints at a frustrated magnetic state slightly above the transition temperature in MnSi.

DOI10.1088/0953-8984/20/23/235222
Alternate JournalJ. Phys.-Condes. Matter