Suppression of electron correlations in the collapsed tetragonal phase of CaFe2As2 under ambient pressure demonstrated by As75 NMR/NQR measurements
نویسندگان
چکیده
The static and the dynamic spin correlations in the low-temperature collapsed tetragonal and the hightemperature tetragonal phase in CaFe2As2 have been investigated by As75 nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. Through the temperature (T) dependence of the nuclear spin lattice relaxation rates (1/T1) and the Knight shifts, although stripe-type antiferromagnetic (AFM) spin correlations are realized in the high-temperature tetragonal phase, no trace of the AFM spin correlations can be found in the nonsuperconducting, low-temperature, collapsed tetragonal (cT) phase. Given that there is no magnetic broadening in As75 NMR spectra, together with the Tindependent behavior of magnetic susceptibility χ and the T dependence of 1/T1Tχ, we conclude that Fe spin correlations are completely quenched statically and dynamically in the nonsuperconducting cT phase in CaFe2As2.
منابع مشابه
Pressure suppression of electron correlation in the collapsed tetragonal phase of CaFe2As2: A DFT-DMFT investigation
Subhasish Mandal,1,* R. E. Cohen,1,2 and K. Haule3 1Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA 2Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, United Kingdom 3Department of Physics, Rutgers University, Piscataway, New Jersey 08854, USA (Received 21 May 2014; revised manuscript received 14 July 2014; published 6 ...
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