[Zurück]

H. Niki, Y. Hamamoto, M. Uezu, M. Pieper, E. Gratz, K. Hense, A. Hoser, N. Stüsser, V. Paul-Boncour, A. Markosyan:
"Field induced metamagnetic transition of ErCo₃ studied by NMR";
Journal of Alloys and Compounds, 408-412 (2006), S. 340 - 342.

Magnetic field dependence of NMR resonance frequencies in ferrimagnetic ErCo3 was measured in fields parallel and perpendicular to the c-axis of the crystal up to 8 T at 4.2 K. The zero field powder spectrum at 4.2 K shows three resolved lines at 23, 65, and 96 MHz, which correspond to 3b, 6c, 18h sites of Co, respectively. When field is applied along the c-axis, the resonance frequencies of 96 MHz line increase at about 10.01 MHz/T with increasing field, while those of 23 and 75 MHz lines decrease at the same rate. This means that the hyperfine field Hhf is negative only for the Co 18h site, whereas at 3b- and 6c-Co it is positive. The positive Hhf is resulted from a large contribution of unquenched 3d orbital moments. When field is applied perpendicular to the c-axis, the frequencies of all three resonance lines increase with increasing field, which means that Hhf is negative at all the three Co sites. The resonance frequencies abruptly change around the field between 2 and 3 T due to the field induced metamagnetic transitions caused by the rotations of Er and Co magnetic moments towards the direction of the applied field from the c-axis.

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC05938212

http://dx.doi.org/10.1016/j.jallcom.2005.04.079