Spin fluctuations in the magnetically ordered phase of frustrated pyrochlore systems
نویسندگان
چکیده
Two geometrically frustrated pyrochlore stannates, undergoing long range magnetic order below 1 K, were investigated at very low temperature. Anomalies in the behaviour of hyperfine quantities are found, by 155Gd Mössbauer spectroscopy in Gd2Sn2O7 and by low temperature specific heat measurements in Tb2Sn2O7. They are interpreted in terms of fluctuations of the correlated Gd or Tb spins, using a model two-level system (the nuclear spins) submitted to a randomly fluctuating (hyperfine) field.
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