Direct measurement of the magnetocaloric effect in cementite

• Published in: Journal of magnetism and magnetic materials Vol. 410; pp. 105 - 108
• Main Authors: Kaeswurm, B., Friemert, K., Gürsoy, M., Skokov, K.P., Gutfleisch, O.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.07.2016
• Subjects: Cementite; Cohenite; Curie temperature; Entropy; Ferromagnetic materials; Ferromagnetism; Isotherms; Magnetic properties; Magnetism; Magnetocaloric effect; Refrigeration; Second order phase transition; Cohenite; Second order phase transition; Ferromagnetism; Magnetocaloric effect; Cementite
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2016.02.080

Measurements of the magnetocaloric effect of cementite at its Curie temperature of 475K are presented. An adiabatic temperature change of 1.76±0.01K was measured using a direct measurement technique. The isothermal entropy change was determined from measurements of magnetisation isotherms and was shown to be 3.07JK−1kg−1 in a field change of 2T. The field dependencies of both magnetocaloric properties follow the H2/3 dependence typical for ferromagnetic materials with a second order phase transition. The material may be of interest in magnetocaloric applications such as magnetic refrigeration or thermomagnetic power generation. [Display omitted] •The magnetocaloriceffect of Fe3C was investigated at its Curie temperature of 475K.•First direct measurement of adiabatic temperature change in cementite.•ΔTad=1.77K and ΔS=3.07JK−1kg−1 in 2T.•MCE follows H2/3 dependence typical for second order phase transition.•Possible applications include magnetic refrigeration and heat power conversion.