Low-frequency current fluctuations, i.e., noise, in the quasi-2D van der Waals antiferromagnetic semiconductor FePS₃ with the electronic bandgap of 1.5 eV is investigated. The electrical and noise characteristics of the p-type, highly resistive, thin films of FePS₃ are measured at different temperatures. The noise spectral density is of the 1/f-type over most of the examined temperature range but reveals well-defined Lorentzian bulges, and increases strongly near the Néel temperature T_N = 118 K (f is the frequency). Intriguingly, the noise spectral density attains its minimum at temperature T ≈ 200 K, which is attributed to an interplay of two opposite trends in noise scaling—one for semiconductors and another for materials with the phase transitions. The Lorentzian corner frequencies reveal unusual dependence on temperature and bias voltage, suggesting that their origin is different from the generation—recombination noise in conventional semiconductors. The obtained results are important for proposed applications of antiferromagnetic semiconductors in spintronic devices. They also attest to the power of the noise spectroscopy for monitoring various phase transitions.

中文翻译：

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准二维范德华反铁磁半导体 FePS3 中的低频电子噪声——相变特征

研究了电子带隙为 1.5 eV的准二维范德华反铁磁半导体 FePS _{3 中}的低频电流波动，即噪声。在不同温度下测量p型高电阻 FePS ₃薄膜的电气和噪声特性。噪声谱密度在大部分检查温度范围内为 1/ f型，但显示出明确定义的洛伦兹凸起，并且在尼尔温度T _N  = 118 K附近强烈增加（f是频率）。有趣的是，噪声谱密度在温度T下达到最小值 ≈ 200 K，这归因于噪声缩放中两种相反趋势的相互作用——一种用于半导体，另一种用于具有相变的材料。洛伦兹角频率揭示了对温度和偏置电压的异常依赖，这表明它们的起源与传统半导体中产生复合噪声不同。获得的结果对于反铁磁半导体在自旋电子器件中的拟议应用很重要。他们还证明了噪声光谱监测各种相变的能力。