霍尔效应与汽车上的霍尔器件

在国产桑塔纳、奥迪、红旗、捷达等轿车电路上经常可以看到"霍尔"(Hall)这个名称,如霍尔式电子点火系统中就有一只霍尔传感器,专门给发动机电控单元(ECU)提供电压信号.     

霍尔效应实验的智能化

利用单片系统控制霍尔效应实验过程，智能化地验证霍尔效应理论、测量给定元件的霍尔灵敏度，并且通过磁场的变化模拟了实际的控制系统，从而使学生对霍尔效应的理论、实验及应用有了充分的认识。     

高性能石墨烯霍尔传感器

本文回顾了石墨烯霍尔传感器的相关研究工作.通过改善石墨烯生长转移和霍尔元件的微加工工艺,石墨烯霍尔元件和霍尔集成电路都展示出超越传统霍尔传感器的优异性能.石墨烯霍尔元件的灵敏度、分辨率、线性度和温度稳定性等重要指标都优于传统商用霍尔元件.通过开发一套钝化工艺,霍尔元件的稳定性有了明显提升.结合石墨烯材料的特点,展示了石墨烯在柔性磁传感和多功能传感领域的新颖应用.此外,成功实现了石墨烯/硅互补型金属-氧化物-半导体(CMOS)混合霍尔集成电路,并进行了应用展示.通过发展一套低温加工工艺(不超过180℃),将石墨烯霍尔元件制备在硅基CMOS芯片的钝化层上,从而与硅基CMOS电路实现了单片集成.本文的研究结果表明石墨烯在霍尔磁探测方向拥有重大的性能优势,在产业化应用中有巨大发展潜力.     

发展中的集成霍尔传感器及在高科技领域中的应用

简述集成霍尔传感器的分类、特性及其在物理实验中的应用。并着重介绍其在工业、交通、家电等领域的广泛应用。     

InSb霍尔传感器输出电压温度特性的研究

对InSb霍尔元件在－135～65℃内的霍尔电压的温度特性进行了测量,研究在恒流源和恒压源条件下其输出电压随温度的变化情况,并对其工作温度、线性范围及应用进行了探讨。     

利用霍耳位置传感器测杨氏模量

固体材料杨氏模量是综合性大学和工科院校物理实验中必做的实验之一。该实验可以学习和掌握基本长度和微小位移量测量的方法和手段。探讨了利用霍尔位置传感器的输出电压与位移量线形关系以测量杨氏模量微小位移量的方法。     

霍尔效应实验直流测量法的误差探讨及处理

本首先对霍尔效应测量中的系统误差作了叙述,对系统误差中的热能流引起的不等位电势提出了自己的见解,并对结果进行了评述。     

锗单晶体变温霍尔效应实验数据的处理

采用微机控制和数字式数据采集系统,在变温环境下(77~420 K)对长为6.0 mm、宽为4.0 mm、厚为0.6 mm的锗样品薄片进行霍尔效应相关数据测量;通过对测量的霍尔电压作数据处理得到锗的霍尔系数RH(T)、电导率σ(T)和霍尔迁移率μH(T)与温度的依赖关系.该实验结果对学生理解半导体物理中的相关知识有重要意义.     

霍尔效应的发现

介绍了霍尔的生平,回顾了霍尔在导师罗兰的指导下,发现霍尔效应的历程;分析了罗兰和霍尔在这一研究中发挥的重要作用,以及霍尔在研究工作中的严谨作风和顽强毅力.     

小型烧结炉装置的设计与制作

设计与研制了一种小型的用于制备薄膜样品电接触的烧结炉装置，该装置简单、实用、特别适用于半导体霍尔样品电极的烧结。     

异常霍尔效应和自旋霍尔效应

异常霍尔效应和自旋霍尔效应是在常规霍尔效应的基础上引发出的2种新现象.本文介绍了这2种现象及其原理和潜在的应用.     

量子霍尔效应

从经典的霍尔效应开始,比较系统地、深入浅出地介绍了量子霍尔效应及其所涉及的一些新概念和实际应用。     

Current breakdown of the integer and fractional quantum Hall effects detected by torque magnetometry

We have developed a novel technique that enables measurements of the breakdown of both the integer and fractional quantum Hall effects in a two-dimensional electron system without the need to contact the sample. The critical Hall electric fields that we measure are significantly higher than those reported by other workers, and support the quasi-elastic inter-Landau-level tunnelling model of breakdown. Comparison of the fractional quantum Hall effect results with those obtained on the integer quantum Hall effect allows the fractional quantum Hall effect energy gap to be determined and provides a test of the composite-fermion theory. The temperature dependence of the critical current gives an insight into the mechanism by which momentum may be conserved during the breakdown process.     

用于开放性实验和演示实验的自制磁场测定仪

介绍作设计制作的磁场测定仪的原理、选材、制作、调试、使用方法及相关的讨论，该仪器可测狭小空间的磁场，确定磁场的性质和空间分布，该制作，既可以由教师精心制作为演示仪器，也可以作为开放性实验为大学生开设，本制作和材料均取自废旧仪器中的零散元件，成本十分低廉，如果不计较成本，对电路和元件进行精确优化，并认真定标，还可用于定量测量。     

基于大学物理实验中霍尔元件的保护及探讨

结合大学物理实验教学中霍尔效应的讲解,阐述了霍尔效应的原理,提出了霍尔效应实验的一些改进方法,重点研究了霍尔元件的保护及对霍尔元件的应用进行了探讨.     

Strong nonlinearity and hysteresis of Hall resistance versus magnetization in nickel thin films

The anomalous Hall effect (AHE) in ferromagnetic materials is perhaps one of the oldest unresolved mysteries in physics. First observed in 1881, its mechanism is still a controversial topic today. The question remains whether AHE is caused by intrinsic (Berry phase and band structure) or extrinsic (defect scattering) effects or a combination of both. Here we present experimental observation in nickel thin films that seems to add to the mystery, but may in fact provide crucial clues for ultimately resolving the controversy. The key observation is that the Hall resistivity of nickel films is a strongly nonlinear function of the magnetization and displays clear hysteresis with respect to M. Specifically, at low temperatures, the anomalous Hall coefficient switches between two saturated values under the magnetic field with a narrow transition region, but with a strong hysteresis, in contrast to the slow saturation of the magnetization. The nonlinearity and the hysteresis become more apparent with decreasing temperature or film thickness. Despite the simplicity of the lattice and magnetic structure of nickel films, these results are outside our current understanding of AHE, whether using intrinsic or extrinsic mechanisms of AHE. It presents a challenge for these models, and may be used as a test of validity for both types of theories.     

Anomalous Hall effect and perpendicular magnetic anisotropy in Sm28Fe72 and Sm32Fe68 thin films

Sm₂₈Fe₇₂ and Sm₃₂Fe₆₈ films of 100 nm thickness were grown using DC magnetron sputter deposition and their structure, magnetization, electrical and Hall resistance characteristics were investigated. An increase in electrical resistivity from 4.75×10⁻⁶ to 5.62×10⁻⁶ Ω m and from 2.26×10⁻⁶ to 2.84×10⁻⁶ Ω m for Sm₂₈Fe₇₂ and Sm₃₂Fe₆₈ films, respectively, with decrease in temperature from 300 to 40 K is attributed to the strain induced anisotropy that dominates at lower temperatures. The positive extraordinary Hall coefficients (R_S) are observed for both films at 300 and 80 K. The existence of hysteresis indicates that Sm₂₈Fe₇₂ and Sm₃₂Fe₆₈ films possess perpendicular anisotropy at 300 K. Hysteresis loop becomes narrow at 80 K for both Sm₂₈Fe₇₂ and Sm₃₂Fe₆₈ films. Magnetization measurements at 300 K exhibiting small coercive field values of 31 and 49 Oe for Sm₂₈Fe₇₂ and Sm₃₂Fe₆₈ films, respectively, confirm the existence of perpendicular anisotropy at 300 K.