Realization and regulation of negative magnetoresistance behavior in Dy-doped SnS2 with high Curie temperature

Abstract

The magnetic two-dimensional transition metal dichalcogenides with high Curie temperature play a pivotal role in spintronic devices and exhibit promising application potentials. In this paper, rare earth Dy-doped SnS2 wafers are synthesized through gas–liquid phase deposition and high-temperature, high-pressure processes. The material exhibits comprehensive properties such as ferromagnetism, high Curie temperature (628 K), and large negative magnetoresistance at low magnetic fields over a wide temperature range (55%–4%, 50–350 K). The results of first-principles calculations indicate that it exhibits the half-metallic behavior of electrons with a single spin direction passing through the Fermi level, with a large spin bandgap of 1.7 eV, and a flatband exists near the Fermi level. Therefore, the substitution of Sn with Dy induces a global structural reorganization and disrupts the system's symmetry, resulting in the formation of a flatband near the Fermi level through the occupation of 4f orbital electrons, providing a stable local magnetic moment. Through the orbital hybridization between Dy and S, the ferromagnetic exchange interaction is formed, achieving the ferromagnetism of DyxSn1−xS2. This laid the foundation for the application of magnetoresistive sensors, electromagnetic shielding, and spin field-effect transistors.