Microwave detection of magnetic phase avalanches in La0.225Pr0.4Ca0.375MnO3 manganitesF. Macià1, G. Abril1, N. Domingo1, J. M. Hernandez1, J. Tejada1 and S. Hill2
1 Departament de Física Fonamental, Facultat de Física, Universitat de Barcelona - Avinguda. Diagonal 647, Planta 4, Edifici nou, 08028 Barcelona, Spain, EU
2 Department of Physics, University of Florida - Gainesville, FL 32611, USA
received 9 January 2008; accepted in final form 13 March 2008; published May 2008
published online 22 April 2008
Recent low-temperature studies on La5/8-yPryCa3/8MnO3 (y=3/8) have shown that the occurrence of the first-order transition in these family of perovskites manifests itself in the form of magnetic and electric avalanches. In this paper we report on the detection of such avalanches performing microwave experiments with coaxial resonators (low frequency ~ 3 GHz) and cavities (high frequency ~ 50 GHz) at different temperatures and magnetic fields. Short measuring times enabled us to detect the rapid variation in the energy absorption and/or cavity perturbation of the microwaves due to the occurrence of these phase transitions.
75.10.-b - General theory and models of magnetic ordering.
78.70.Gq - Microwave and radio-frequency interactions.
45.70.Ht - Avalanches.
© EPLA 2008