Regensburg 2002 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

MA: Magnetismus

MA 10: Poster : Dünne Schichten(1-21),Spinabh.Transp.(22-39),Exch.Bias(40-51),Spindyn.(52-55),Mikromag.(56-66),Partikel(67-74),Abb.Verf.(75-77),Oberfl.+Spinelektr.+Elektr.Theo+Mikromag(75-87),PÜ+Aniso+Werkst/Leg.(88-103),Mol.Mag.+N-dim+Messm.+Postdead(104-111

MA 10.95: Poster

Tuesday, March 12, 2002, 15:00–19:00, Bereich A

Heat capacity anomalies of Fe_1+xCr_2−yS_4−δ ferrimagnets — •S. Körner¹, V. Tsurkan^1,2, D. Maurer¹, E.-W. Scheidt¹, D. Samusi², and R. Tidecks¹ — ¹Institute of Physics, University of Augsburg, Universitaetsstrasse 1, D-86159, Augsburg, Germany — ²Institute of Applied Physics, Moldova Academy of Sciences, Chisinau, MD-2028, R. Moldova

A strong influence of iron and sulphur non-stoichiometry on the heat capacity C_H=0 of poly- and single crystalline Fe_1+xCr_2−yS_4−δ samples was found at temperatures below 10 K. An increase of δ significantly enhances a λ-anomaly-like heat capacity maximum observed in polycrystals and shifts it to higher temperatures, whereas deficit and excess of iron suppress this maximum and shift it into the opposite direction. Below 5K the value of C_H=0 for single crystals is much higher than for polycrystals and changes like T² in the range 0.1-1 K. The obtained results combined with the anomalies of magnetic and elastic properties give evidence for a structural transformation due to strong spin- lattice coupling.