Dresden 2006 – scientific programme

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MA: Magnetismus

MA 14: Magnetic Thin Films II

MA 14.6: Talk

Tuesday, March 28, 2006, 11:30–11:45, HSZ 03

Investigating pinning dominated domain reversal in epitaxial SmCo thin films — •Aarti Singh¹, Volker Neu¹, Roland Tamm², Karavati Subbarao², Sebastian Fähler¹, Werner Skrotzki², Ruben Hühne¹, Ludwig Schultz¹, and Bernhard Holzapfel¹ — ¹IFW Dresden, Institute of Metallic Materials, P.O. Box 270116, D-01171 Dresden, Germany — ²Institute of Structural Physics, Dresden University of Technology, 01062 Dresden, Germany

Epitaxially grown SmCo₅ thin films with strong magnetic anisotropy serve as suitable candidates for understanding the basic mechanisms governing coercivity development in these films. The films were epitaxially prepared by pulsed laser deposition on Cr buffered MgO(110) substrates. The epitaxial relation : MgO(110)[001] || Cr(211)[011] || SmCo(100)[001] is confirmed by pole figure measurements and magnetic measurements. The remanence ratio for the two in-plane directions ( || MgO[110] and || MgO[001] ) is as low as 0.05, and the estimated in-plane anisotropy is 28 T. Along the easy axis, the maximum energy product, (BH)_max is 160 kJ/m³ , remanence is 0.96 T and coercivity more than 3 T. For evaluating the cause of high coercivities, a temperature dependent coercivity analysis and angle dependent coercivity analysis were done. In both the analyses the results contradict the simple nucleation dominated coercivity mechanism and are better explained by a pinning dominated magnetisation reversal. The large number of grain boundaries due to small grain sizes and stacking faults within the SmCo₅ crystallites are discussed as possible pinning centres.