Effect of Pressure on the Curie Point of the Pseudo‐NiAs‐Type Cr₃Te₄

Abstract

Rxagnetic induction and electrical resistivity of Cr3uTe4 including vacancies of magnetic atoms have been investigated in the vicinity of the Curie temperatures a t hydrostatic pressures up to 6 kbar. The magnetic induction smoothly vanishes at the Curie temperature, T, = 325 OK. The electrical resistivity shows a T-type anomaly with a kink a t 319 "K and atmospheric pressure, and this temperature is in agreement with the Curie temperature.The pressure effect on the Curie point has been obtained as: (dT,/dP) = -(6.2 f 0.4) deg/ kbar from the magnetic induction, and (dT,/dP) = -(5.9 1 0 . 3 ) deg/kbar from the electrical resistivity measurements. Although a large number of exchange chains are cut by the vacancies in CrJJTe,, only little difference has been observed in the Curie temperatures between CrTe and Cr,mTe4. This is not explained by a volume effect of exchange integral on the Curie temperature with dT,/dP < 0 in Cr,lJTe,, and a brief discussion of exchange interactions in this compound has been done in comparison with those in CrTe on the basis of the ionic model.Die magnetische lnduktion und die elektrische Leitfahigkeit von Cr,OTe,, das Leerstellen von magnetischen Atomen enthiilt, wurde in der Nahe der Curietemperatur bei hydrostatischen Drucken bis zu 6 kbar untersucht. Die magnetische Induktion verschwindet langsam bei der Curietemperatur T, = 325 OK. Die elektrische :Leitfahigkeit zeigt eine Anomalie vom r -T y p mit einem Sprung bei 319 "K und Atmospharendruck; die Temperatur stimmt mit der Curietemperatur uberein. Fur die Druckabhgngigkeit des Curiepunktes wurde aus Messungen der magnetischen Induktion (dT,/dP) = -(6,2 * 0,4) grd/kbar und der elektrischen Leitfahigkeit (dTJdP) = -(5,9 + 0,3) grdlkbar gefunden. Obwohl eine groBe Anzahl von Austauschketten durch die Leerstellen in Cr30Te, geschnitten werden, wurde nur eine geringe Differenz der Curietemperaturen von CrTe und Cr3UTe, beobachtet. Dies kann nicht durch einen VolumeneinfluB des Austauschintegrals auf die Curietemperatur mit dT,/dP < 0 in Cr3[7Te4 erklart werden. Eine kurze Diskussion der Austauschwechselwirkungen in dieser Verbindung wird in Vergleich zu der in CrTe auf der Grundlage eines Ionenmodells dnrchgefuhrt.

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

“…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.…”

Effect of pressure on the Néel and the ferrimagnetic Curie temperatures of FeS1+δ

“…and FeSlSo4 at atmospheric pressure, and found v-shaped 1.00 in this work. Electrical and Fe Se magnetic structures which a r e essentially similar to that of FeS (lo), but they contain the considerably larger amounts of vacancies as the magnetic lattice defects (11) in iron sublattices. This is one of the marked differences among these iron chalcogenides.…”