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 6/ 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 = 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 = 0.03 J/(mol·K), 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 , 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 (, 1.95% at 300 K and 14 T) to negative (, −30.73% at 14.25 K and 14 T) as the temperature decreases. This behavior could be attributed to spin-disordered scattering.

中文翻译：

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EuAgP 半导体中具有符号反转的晶体、铁磁性和磁阻

我们合成了铁磁EuAgP半导体，并对其晶体、磁性、热容、带隙和磁阻特性进行了全面研究。我们的研究结合了 X 射线衍射、光学和 PPMS DynaCool 测量。EuAgP采用六方结构，空间群为6/。随着温度降低，它经历从高温顺磁性到低温铁磁性的磁相变。通过使用居里-韦斯定律拟合测量的磁化率，我们确定铁磁转变温度 = 16.45(1) K。EuAgP 的热容分析考虑了电子、声子和磁子的贡献，显示 = 0.03 J/(mol·K)，表明半导体行为。此外，我们根据吸收光谱测量计算出~1.324(4) eV 的带隙。在没有施加磁场的情况下测量的 EuAgP 的电阻率与温度的关系在 附近显示出明显的峰值，随着施加磁场的增加，该峰值迅速减小，范围为 1 到 14 T。一种有趣的现象以明显的磁阻转变的形式出现，随着温度降低，从正值（300 K 和 14 T 时为 1.95%）变为负值（14.25 K 和 14 T 时为-30.73%）。这种行为可归因于自旋无序散射。