Europhys. Lett., 53 (5) , pp. 667-672 (2001)
The spin-Peierls compound MEM(TCNQ)2: Evidence for the non-universality of the magnetic phase diagramL. Weckhuysen1, S. V. Demishev2, A. V. Semeno1, J. Vanacken1, L. Trappeniers1, A. A. Pronin2 and V. V. Moshchalkov1
1 Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven 3001 Leuven, Belgium
2 Low Temperatures Laboratory, General Physics Institute - 117942 Moscow, Russia
(Received 9 October 2000; accepted in final form 14 December 2000)
The spin-Peierls state in the organic compound MEM(TCNQ)2 is studied by magnetisation measurements in magnetic fields up to 50. The possible universality of the magnetic field vs. temperature magnetic phase diagram of spin-Peierls systems is investigated by comparing the results on MEM(TCNQ)2 with the corresponding data for the inorganic spin-Peierls compound . Although the transition line between the uniform and the dimerised phase follows the same dependence for both compounds, strong discrepancies are found for the phase boundary between the dimerised and the high-field magnetic phase.
75.30.Kz - Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.).
75.60.Ej - Magnetization curves, hysteresis, Barkhausen and related effects.
75.50.Ee - Antiferromagnetics.
© EDP Sciences 2001