Crystal, ferromagnetism, and magnetoresistance with sign reversal in a EuAgP semiconductor

Autor: Qian Zhao, Kaitong Sun, Si Wu, Hai-Feng Li
Jazyk: angličtina
Rok vydání: 2025
Předmět:
Zdroj: Journal of Materiomics, Vol 11, Iss 1, Pp 100853- (2025)
Druh dokumentu: article
ISSN: 2352-8478
DOI: 10.1016/j.jmat.2024.02.012
Popis: We synthesized the ferromagnetic EuAgP semiconductor and conducted a comprehensive study of its crystalline, magnetic, heat capacity, band gap, and magnetoresistance properties. Our investigation utilized a combination of X-ray diffraction, optical, and PPMS DynaCool measurements. EuAgP adopts a hexagonal structure with the P63/mmc space group. As the temperature decreases, it undergoes a magnetic phase transition from high-temperature paramagnetism to low-temperature ferromagnetism. We determined the ferromagnetic transition temperature to be TC = 16.45(1) K by fitting the measured magnetic susceptibility using a Curie-Weiss law. Heat capacity analysis of EuAgP considered contributions from electrons, phonons, and magnons, revealing η = 0.03 J/(mol·K2), indicative of semiconducting behavior. Additionally, we calculated a band gap of ∼1.324(4) eV based on absorption spectrum measurements. The resistivity versus temperature of EuAgP measured in the absence of an applied magnetic field shows a pronounced peak around TC, which diminishes rapidly with increasing applied magnetic fields, ranging from 1 to 14 T. An intriguing phenomenon emerges in the form of a distinct magnetoresistance transition, shifting from positive (e.g., 1.95% at 300 K and 14 T) to negative (e.g., −30.73% at 14.25 K and 14 T) as the temperature decreases. This behavior could be attributed to spin-disordered scattering.
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