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Register a new userHeat capacity and Mosssbauer study of Self flux grown FeTe Single Crystal
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Authors
P. K Maheshwari
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We report mainly the heat capacity and Mossbauer study of self flux grown FeTe single crystal, which is ground state compound of the Fe chalcogenides superconducting series, i.e., FeTe1-x(Se/S)x. The as grown FeTe single crystal is large enough to the tune of few cm and the same crystallizes in tetragonal structure having space group of P4/nmm. FeTe shows the structural/magnetic phase transition at 70K in both magnetic and resistivity measurements. Heat capacity measurement also confirms the coupled structural/magnetic transition at the same temperature. The Debye model fitting of low temperature (below 70K) heat capacity exhibited Debye temperature to be 324K. MOssbauer spectra are performed at 300K and 5K. The 300K spectra showed two paramagnetic doublets and the 5K spectra exhibited hyperfine magnetic sextet with an average hyperfine field of 10.6Tesla matching with the results of Yoshikazu Mizuguchi et al.
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We report results of 75As nuclear magnetic resonance (NMR) experiments on a self-flux grown single crystal of BaFe2As2. A first-order antiferromagnetic (AF) transition near 135 K was detected by the splitting of NMR lines, which is accompanied by simultaneous structural transition as evidenced by a sudden large change of the electric field gradient tensor at the As site. The NMR results lead almost uniquely to the stripe spin structure in the AF phase. The data of spin-lattice relaxation rate indicate development of anisotropic spin fluctuations of the stripe-type with decreasing temperature in the paramagnetic phase.
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