New Fe-based layered telluride Fe3-delta As1-yTe2: synthesis, crystal structure and physical properties

作者：Verchenko Valeriy Yu^*; Sokolov Sergei S; Tsirlin Alexander A^*; Sobolev Alexey V; Presniakov Igor A; Bykov Mikhail A; Kirsanova Maria A; Shevelkov Andrei V

来源：Dalton Transactions, 2016, 45(42): 16938-16947.

DOI：10.1039/c6dt02721k

A new ternary telluride, Fe3-delta As1-yTe2, was synthesized from elements at 600 degrees C. It crystallizes in the hexagonal P6(3)/mmc space group with the unit cell parameters a = 3.85091(9) angstrom and = 17.1367(4) angstrom for delta = 0.3 and y = 0.04. Its layered crystal structure contains partially occupied intralayer and interlayer Fe positions, which give rise to significant nonstoichiometry: Fe3-delta As1-yTe2 was found to possess the homogeneity range of 0.25 < delta < 0.45 and y = 0.04. Regions of local vacancy ordering alternate with regions of randomly distributed vacancies, so that the ordering of Fe atoms and vacancies is not complete in the average structure. Clear evidence of the magnetic phase transition is obtained by thermodynamic measurements, Mossbauer spectroscopy, and neutron powder diffraction. Magnetic susceptibility measurements reveal weak ferromagnetism below T-C = 123 K with a net moment of M-S similar to 0.1(mu B)/Fe at T = 2 K. This transition is confirmed by differential scanning calorimetry. Additionally, neutron powder diffraction indicates the onset of a complex AFM-like magnetic ordering below 100 K.

• 出版日期2016