Synthesis and physical properties of a new layered ferromagnet, Cr1.21Te2

Abstract

Single crystals of a new layered compound, Cr1.21Te2, was synthesized via a vapor transport method. The crystal structure and physical properties were characterized by single crystal and powder x-ray diffraction, temperature- and field-dependent magnetization, zero-field heat capacity and angle-resolved photoemission spectroscopy. Cr1.21Te2, containing two Cr sites, crystalizes in a trigonal structure with a space group P-3 (No. 147). The Cr site in the interstitial layer is partially occupied. Physical property characterizations indicate that Cr1.21Te2 is metallic with hole pockets at the Fermi energy and undergoes a ferromagnetic phase transition at ~173 K. The magnetic moments align along the c-axis in the ferromagnetic state. Based on low temperature magnetization, the spin stiffness constant D and spin excitation gap $\hat{I}”$ were estimated according to Bloch's law to be D = 99 $\pm$ 24 meV ${\tilde{A}}^2$ and $\hat{I}”$ = 0.46 $\pm$ 0.33 meV, suggesting its possible application as a low dimensional ferromagnet.

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