Effect of Co and Ni substitution on the two magnetostructural phase transitions inFe1.12Te

Abstract

Here we present the results of high-resolution x-ray diffraction experiments along with specific heat, resistivity, and magnetization measurements of chemically well-characterized Fe 1.12−x M x Te (M = Co, Ni) samples. The motivation is to investigate how the two coupled magnetostructural phase transitions in the antiferromagnetic parent compound Fe 1.12 Te of chalcogenide superconductors can be tuned. While the two-step magnetostructural transition (tetragonal-to-orthorhombic followed by orthorhombic-to-monoclinic) persists in Fe 1.10 Co 0.02 Te, only one, tetragonal-to-orthorhombic transition was observed in Fe 1.10 Ni 0.02 Te. Upon increasing the Co and Ni substitution, the structural phase transitions and the long-range magnetic order are systematically suppressed without any sign of superconductivity. For high substitution levels (x 0.05), a spin-glass-like behavior was observed and the low-temperature structure remains tetragonal. From our results, it can be inferred that the electron doping strongly suppresses the magnetostructural phase transitions.

Observation of non-Fermi liquid behavior in hole-dopedLiFe1−xVxAs

“…Yet, an even higher effective magnetic moment of about 4 µ B has been reported in Fe 1+x Te and explained by a Kondo-type behavior (i.e. with local magnetic moments entangled with itinerant electrons) [35][36][37]. Similarly, V dopants are likely to give rise to magnetic impurities and induce entanglement between the local magnetic moments and the itinerant electrons.…”

Synthesis, phase stability, structural, and physical properties of 11‐type iron chalcogenides

“…The results of neutron scattering indicated the presence of local moments. Indeed, above the antiferromagnetic ordering temperature , the magnetic susceptibility follows a Curie–Weiss behavior (). The value of the total spin S calculated from the Curie constant was found to be S = 3/2, which is also consistent with the value obtained from the inelastic neutron scattering .…”

“…Instead, it shows a very rich interplay of localized and itinerant magnetism . Moreover, magnetostructural phase transitions have been observed when tuning parameters such as temperature, composition, or pressure were varied . As a digression, while can be dramatically increased in FeSe monolayers , superconductivity has been found in FeTe when fabricated in the form of thin films () or heterostructures ().…”