Regensburg 2016 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 17: Poster Session I

MA 17.77: Poster

Dienstag, 8. März 2016, 09:30–12:30, Poster B1

Study of candidate compounds for magnetocaloric materials in the system Mn2-xMxSb (M=Fe, Co) — •Mamuka Chikovani, Karen Friese, Paul Hering, Jörg Voigt, Jörg Perßon, and Thomas Brückel — JCNS-2/PGI 4, Forschungszentrum Jülich GmbH, Germany

Magnetocaloric refrigeration is an emerging technology in today*s cooling devices and it has a potential to save about 20-30 % of energy compared to conventional vapor compression technology. Nowadays, the most important issue is to find cheap and abundant materials exhibiting a sizable magnetocaloric effect. We report on preparation and characterization of compounds of general composition * Mn2-xMxSb system with M = (Fe, Co). The substitution on the Mn site has an effect on magnetic properties and magnetic transitions. We synthesized samples of different stoichiometry by inductive melting of the elements in a cold crucible and performed studies using x-ray powder diffraction method and macroscopic magnetization measurements. Based on these data we could then calculate the entropy change. In the Fe-containing samples, in particular in Mn1.8Fe0.2Sb, we observe a small MCE associated to a paramagentic-ferrimagnetic phase transition. The Co-doped samples reveal a sizeable MCE accompanying a ferri-to-antiferromagnetic phase transition. Currently we study the response of the lattice parameter to the magnetic transitions with low temperature powder diffraction (300-15 K).