Specific heat of Gd4Co3

• Type: Article in International Scientific Journal
• Date: 2010

Authors

T.M. Seixas (Author) FCUP; M.A. Salgueiro da Silva (Author) FCUP; O.F. de Lima (Author) Other; J. Lopez (Author) Other; H.F. Braun (Author) Other; G. Eska (Author) Other

Journal

Title: Journal of Physics Condensed Matter

Vol. 22 No. 13

Initial page: 136002

ISSN: 0953-8984

Publisher: Institute of Physics Publishing

Indexing

ISI Web of Knowledge - 13 Citations

ISI Web of Science

Scopus - 13 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-003-7HV

Abstract (EN): The specific heat (C(T)) of Gd4Co3 was measured in the temperature range 2-300 K and its magnetic contribution (C-m(T)) was determined using a new method that fits the electronic specific heat coefficient (gamma) and the Debye temperature (theta(D)) by constraining the resulting magnetic entropy (S-m(T)) to saturate at temperatures far above the Curie temperature (T-C). C-m(T) exhibits a low-temperature bump originating from thermal excitation of gapped spin waves, which is responsible for pronounced peaks, at approximate to 35 K, in both C-m/T and the temperature derivative of the magnetic contribution to electrical resistivity (d rho(m)/dT). Apart from in the vicinity of T-C, an excellent global correlation was found between C-m/T and d rho(m)/dT. Our results provide strong support for the consistency of the new method proposed for the determination of C-m(T) and rule out any major role of short-range order on Gd moments or d-electron spin fluctuation effects in the paramagnetic phase. A comparative analysis with other methods used in similar compounds points to the need for a better evaluation of C-m(T) in such compounds, especially in the magnetically ordered phase, where a deficient evaluation of C-m/T has a larger impact on the S-m(T) curve.

Language: English

Type (Professor's evaluation): Scientific