Identifying the critical point of the weakly first-order itinerant magnet DyCo2 with complementary magnetization and calorimetric measurements

TitleIdentifying the critical point of the weakly first-order itinerant magnet DyCo2 with complementary magnetization and calorimetric measurements
Publication TypeJournal Article
Year of Publication2013
AuthorsMorrison K, Dupas A, Mudryk Y, Pecharsky VK, Gschneidner KA, Caplin AD, Cohen LF
Journal TitlePhysical Review B
Volume87
Pages134421
Date Published04
Type of ArticleArticle
ISBN Number1098-0121
Accession NumberWOS:000318174600003
Keywordsband model, ferromagnetism, fields, intermetallics, metamagnetism, order, phase-transitions, system
Abstract

We examine the character of the itinerant magnetic transition of DyCo2 by different calorimetric methods, thereby separating the heat capacity and latent heat contributions to the entropy-allowing direct comparison to other itinerant electron metamagnetic systems. The heat capacity exhibits a large lambda-like peak at the ferrimagnetic ordering phase transition, a signature that is remarkably similar to La(Fe,Si)(13), where it is attributed to giant spin fluctuations. Using calorimetric measurements, we also determine the point at which the phase transition ceases to be first order: the critical magnetic field, mu H-0(crit) = 0.4 +/- 0.1 T and temperature T-crit = 138.5 +/- 0.5 K, and we compare these values to those obtained from analysis of magnetization by application of the Shimizu inequality for itinerant electron metamagnetism. Good agreement is found between these independent measurements, thus establishing the phase diagram and critical point with some confidence. In addition, we find that the often-used Banerjee criterion may not be suitable for determination of first order behavior in itinerant magnet systems. DOI: 10.1103/PhysRevB.87.134421

URL<Go to ISI>://WOS:000318174600003http://prb.aps.org/pdf/PRB/v87/i13/e134421
DOI10.1103/PhysRevB.87.134421