The van der Waals Ferromagnets Fe5-delta GeTe2 and Fe5-delta-xNixGeTe2 - Crystal Structure, Stacking Faults, and Magnetic Properties

Stahl, Juliane; Shlaen, Evgeniya and Johrendt, Dirk (2018): The van der Waals Ferromagnets Fe5-delta GeTe2 and Fe5-delta-xNixGeTe2 - Crystal Structure, Stacking Faults, and Magnetic Properties. In: Zeitschrift für Anorganische und Allgemeine Chemie, Vol. 644, No. 24: pp. 1923-1929

Abstract

Fe5-delta GeTe2 was synthesized by heating the elements at 1050 K and characterized by single crystal and powder X-ray analysis. The structure [R3m, a = 4.0376(4) angstrom, c = 29.194(6) angstrom] consists of Fe5-delta Ge layers separated by tellurium double layers forming a van der Waals gap. The pronounced two-dimensional character of Fe5-delta GeTe2 causes stacking faults along the c direction. Simulations of different stacking variants using the DIFFaX software reveal disorder occurring in domains. Magnetic measurements of Fe5-delta GeTe2 show ferromagnetism below 279 K with a saturation moment of 1.80 mu(B) at 1.8 K. Nickel substitution of the iron sites has little influence on the structure but changes the saturation moment, which passes through a maximum of 2.11 mu(B) in Fe4.11Ni0.50GeTe2. This indicates that structural influences as well as the dilution of the magnetic iron atoms play a decisive role.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0044-2313
• Language: English