posted on 2013-06-28, 11:31authored byKelly MorrisonKelly Morrison, A. Dupas, Y. Mudryk, V.K. Pecharsky, K.A. Gschneidner, A.D. Caplin, L.F. Cohen
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 λ-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, μ0Hcrit = 0.4 ± 0.1 T and temperature Tcrit = 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.
History
School
Science
Department
Physics
Citation
MORRISON, K. ... et al., 2013. Identifying the critical point of the weakly first-order itinerant magnet DyCo2 with complementary magnetization and calorimetric measurements. Physical Review B, 87 (13), 6pp.