Effect of pressure on the Curie point of Cr1−δTe system with the Pseudo-NiAs-type structure

Abstract

Pressure effect on the Curie temperature in Cr3□Te4 (quenching temperature 1000 °C) with the partially disordered phase of MLD and in Cr7□Te8 (1000 °C) with the disordered phase of MLD, and in Cr7□Te8 (400 °C) with the ordered phase have been supplementarily investigated by the electrical resistivity measurements and the magnetic induction method, in addition to the previous works. The shifting rates in TC with increase of hydrostatic pressures up to 5 kbar were determined as: dTC/dP = − (5.9 ± 0.1) deg/kbar and dTC/dP = − (6.3 ± 0.1) deg/kbar for Cr3□Te4 (1000 °C) by the magnetic induction and the electrical resistivity measurements, respectively, and dTC/dP = − (6.9 ± 0.4) deg/kbar for Cr7□Te8 (1000 °C), dTC/dP = − (5.3 ± 0.2) deg/kbar for Cr7□Te8 (400 °C) by the electrical resistivity measurements. Little difference in TC at atmospheric pressure and in the pressure effect on TC have been observed between Cr3□Te4 (1000 °C) and Cr3□Te4 (cooled slowly), unlike in the case of Cr7□Te8. The magnetic exchange interaction in the MLD‐type compound Cr1−δTe is also discussed.

Pressure-Induced Structural Phase Transition, Anomalous Insulator-to-Metal Transition, and n–p Conduction-Type Switching in Defective, NiAs-Type Cr1−δTe

“…According to the previously reported results of electrical transport measurements and theoretical calculations, ,,− CrTe, Cr 3 Te 4 , and Cr 5 Te 8 exhibit metallic conductive behaviors at ambient pressure. The electrical transport behaviors of these three samples become very complex due to the existence of defects and disordered states upon compression (Figure d–g).…”

“…At present, there are few studies on the structure and physical properties of these compounds under pressure. Only magnetic-related properties of these compounds have been preliminary studied at low pressures. − Therefore, it is necessary to further study the Cr–Te materials under HP to understand the impact of vacancy concentrations (δ) on the structure–property relationship, which is of great significance to the exploration of functional materials with NiAs-type structures.…”

Magnetic properties and low temperature X-ray studies of the weak ferromagnetic monoclinic and trigonal chromium tellurides Cr5Te8

“…In addition, ferromagnetic exchange is more effective when Cr-Te-Cr angles approach 90 as it is the case on going from m-Cr 5 Te 8 to tr-Cr 5 Te 8 . We note that for ferromagnetic Cr 3 Te 4 T c strongly depends on the actual composition and values between 315 K and about 350 K were reported [29,[35][36][37][38][39][40][41][42].…”

Spin-glass-like behavior and electrical transport properties ofCr7(Se1−xTex)Li1, Zhang2, Li3 et al. 2006Phys. Rev. B12051View full textAdd to dashboardCite

“…As a consequence of this diversity they have excited considerable interest. It is known that Cr 7 Se 8 has a monoclinic structure with an ordered arrangement of vacant chromium sites, which is antiferromagnetic with a Néel temperature T N of about 162 K. 2 On the other hand, Cr 7 Te 8 has the same crystal structure as Cr 7 Se 8 , which is ferromagnetic with a Curie temperature T C of about 330 K. 3 Similar to the Mn 1−x Cr x Te system, 4 they have the same crystal structure and comparatively small difference in their lattice constants. In this work, we attempt to combine Cr 7 Se 8 and Cr 7 Te 8 together, expecting a complete solid solution in the Cr 7 ͑Se 1−x Te x ͒ 8 system and unusual changes near x = 0.3 since it orders ferromagnetically for x Ͼ 0.3 as reported in Ref.…”

“…Meanwhile, Cr 7 Se 8 appears to be a semiconductor, whereas Cr 7 Te 8 is a metal conductor. 3 It is interesting to detect if there exist some abnormal electrical transport properties at a certain composition region. Hence, in this paper, the magnetic and electrical transport properties of Cr 7 ͑Se 1−x Te x ͒ 8 compounds are investigated.…”