Low-field microwave absorption in Gd2CuO4: similarity and contrast with high-temperature superconducting materials
1990; Elsevier BV; Volume: 170; Issue: 1-2 Linguagem: Inglês
10.1016/0921-4534(90)90225-4
ISSN1873-2143
AutoresM.D. Sastry, K.S. Ajayakumar, R.M. Kadam, G.M. Phatak, R.M. Iyer,
Tópico(s)Magnetic properties of thin films
ResumoA low-field microwave absorption signal observed in Gd2CuO4 below 260 K in EPR spectrometric measurements has features strickingly similar to those reported for high-temperature superconductors below Tc. It has opposite phase compared to that of EPR absorption of Gd3+ and is found to exhibit hysteresis effects on magnetic field cycling. Furthermore, the difference between zero-field cooled and field cooled samples is found to be similar to that expected for magnetization in spin glasses. The only contrasting feature, as compared to superconducting samples, is in the relative position of the signal during field increasing and decreasing cycles and this feature is shown to be most important in distinguishing the genuine signature of superconductivity. The possible consequences of the present observation on the mechanism of superconductivity are discussed.
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