标题： 交换偏置多环平面霍尔磁阻传感器在非屏蔽环境中的nT分辨率 显示英文标题

标题： Exchange-Biased multi-ring Planar Hall Magnetoresistive Sensors with nT resolution in Non-Shielded Environments

摘要： 平面霍尔磁阻传感器（PHMR）由于其高灵敏度、低功耗和与集成电路技术的兼容性，是各种磁传感应用的有前途的候选者。 然而，其性能通常受到固有噪声源的限制，影响其分辨率和整体灵敏度。 在这里，研究了三种双层结构 NiFe(10 nm)/IrMn(10 nm)，NiFe(30 nm)/IrMn(10 nm)，以及NiFe(30 nm)/IrMn(20 nm)在低频（直流-25 Hz）下的噪声水平的影响。 本研究包括对多环PHMR传感器优化过程和噪声特性的详细研究，重点是识别和量化主要噪声源。 实验测量得到了包括热噪声、1/f噪声、混合和环境噪声在内的噪声源的理论分析的补充。 在室温下非屏蔽环境中，在10 Hz时观察到NiFe(30 nm)/IrMn(10 nm)结构的最佳磁分辨率，检测限低于1.5 nT/sqrt(Hz)。 此外，通过在250摄氏度下退火1小时，观察到灵敏度的显著提高。 本研究的发现有助于更深入地理解PHMR传感器中的噪声行为，为在低频下开发提高其性能的策略铺平了道路，以满足苛刻的传感应用需求。 显示英文摘要

摘要： Planar Hall magnetoresistive sensors (PHMR) are promising candidates for various magnetic sensing applications due to their high sensitivity, low power consumption, and compatibility with integrated circuit technology. However, their performance is often limited by inherent noise sources, impacting their resolution and overall sensitivity. Here the effect of three bilayer structures NiFe(10 nm)/IrMn(10 nm), NiFe(30 nm)/IrMn(10 nm), and NiFe(30 nm)/IrMn(20 nm) on noise levels is investigated at low-frequency (DC - 25 Hz). This study includes a detailed investigation on the optimization process and noise characteristics of multiring PHMR sensors, focusing on identifying and quantifying the dominant noise sources. The experimental measurements are complemented by a theoretical analysis of noise sources including thermal noise, 1/f noise, intermixing and environmental noise. The best magnetic resolution is observed for the NiFe(30 nm)/IrMn(10 nm) structure, which achieves a detectivity below 1.5 nT/sqrt(Hz) at 10 Hz in a non-shielded environment at room temperature. In addition, a substantial improvement in sensitivity is observed by annealing the sensors at 250 deg C for 1 hour. The findings of this study contribute to a deeper understanding of noise behavior in PHMR sensors, paving the way for developing strategies to improve their performance for demanding sensing applications at low frequencies.