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| 脉冲强磁场下的电极化测量系统 | |
| 引用本文： | 刘婉馨,陈瑞,刘永杰,王俊峰,韩小涛,杨明. 脉冲强磁场下的电极化测量系统[J]. 物理学报, 2020, 0(5): 218-224 |
| 作者姓名： | 刘婉馨 陈瑞 刘永杰 王俊峰 韩小涛 杨明 |
| 作者单位： | 华中科技大学物理学院国家脉冲强磁场科学中心 |
| 基金项目： | 国家自然科学基金(批准号:11574098,51821005);华中科技大学自主创新基金重点项目(批准号:2172018KFYXKJC005)资助的课题~~ |
| 摘 要： | 多铁性材料是当前物质科学研究的热点,具有重要的科学研究意义和应用前景.低温和强磁场实验环境为研究多铁性材料提供了一种有效途径.脉冲强磁场下的电极化测量系统能实现最高磁场强度60 T、最低温度0.5 K的铁电特性测量.该系统采用热释电方法,具有磁场强度高、控温范围广、转角测量等特点,可用于强磁场下的磁电特性研究.本文介绍了该系统的测量装置和实验原理,并展示了其在多铁性材料研究中的一系列应用,揭示了脉冲强磁场电极化测量系统在磁电特性探索中的重要作用. |
| 关 键 词： | 脉冲强磁场 电极化 多铁性材料 磁电特性 |
A pulsed high magnetic field facility for electric polarization measurements |
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| Liu Wan-Xin,Chen Rui,Liu Yong-Jie,Wang Jun-Feng,Han Xiao-Tao,Yang Ming. A pulsed high magnetic field facility for electric polarization measurements[J]. Acta Physica Sinica, 2020, 0(5): 218-224 | |
| Authors: | Liu Wan-Xin Chen Rui Liu Yong-Jie Wang Jun-Feng Han Xiao-Tao Yang Ming |
| Affiliation: | (Wuhan National High Magnetic Field Center,School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China) |
| Abstract: | Multiferroic materials, which exhibit the coexistence of ferromagnetic, ferroelectric, or ferroelastic orders,are of particular interest for not only fundamental physics but also potential applications. An important physical property of multiferroic materials, especially those with magnetically driven ferroelectricity, is known as a strong magnetoelectric coupling between the magnetic order and the ferroelectric order. The external magnetic fields can directly interact with spins or magnetic moments of the materials and lead the spontaneous ferroelectricity to be suppressed, and in some cases result in field-induced ferroelectricity in a higher field.Depending on the exchange interactions, these ferroelectric phase transitions may take place in a critical magnetic field as high as several tens of tesla. The standard electric-polarization measurement based on a commercial PPMS system is limited by the strength of the static field consequently. As an extremely experimental condition, pulsed magnetic fields can be used to reveal new physical phenomena in multiferroic materials. Due to the short pulse duration and the effect of eddy current, this measurement technique under pulsed high magnetic fields is still a challenge to date although a few laboratories have developed it in recent years.Wuhan National High Magnetic Field Center(WHMFC) of China is a newly built pulsed-field laboratory.This experimental station is equipped with the many measuring instruments such as for measuring electric transport, magnetization, electron spin resonance, magneto-optics, and high pressure, which were established after the national assessment at the end of 2014. Recently, using a pyroelectric technique we successfully constructed an electric-polarization measurement system based on the large-scaled facility at the WHMFC. The nondestructive magnet driven by discharging a 1.25 MJ capacitor bank can generate a pulsed field up to 60 T.By tuning the charging energy and voltages, the pulse duration time can be modulated from 4.3 ms to 10.8 ms.A helium-3 cryogenic system equipped on this facility can achieve a lowest temperature down to 0.5 K. A highprecision rotation probe is designed and fabricated with angle varying from –5° to 185° for an angulardependent study. The pyroelectric current is detected by a shunt resistor of 10 k W and the electric polarization is derived by integrating the pyroelectric current over the time. The resulting data have a good accuracy and quality which are helpful in detecting weak ferroelectric phase transitions induced by pulsed fields with a fast field sweep rate. In this paper, we introduce this measurement system in detail including the method, principle and its advantages in comparison with those in static fields. Recent study and progress of magnetoelectric multiferroic materials under high magnetic fields are also reported. |
| Keywords: | high magnetic fields electric polarization multiferroics magnetoelectric properties |
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