【摘要】：隨著科技的發(fā)展,人們對器件小型化的需求越來越高,這就需要探索同時具有兩種或著兩種以上功能的新材料,以研制能夠同時實現(xiàn)多種功能的新型器件。多功能材料,尤其是磁電材料一直受到研究者的廣泛關(guān)注。但是,磁電材料中磁電耦合效應(yīng)一般都非常微弱,傳統(tǒng)的測量手段很難得到有效的磁電耦合信號,嚴(yán)重影響磁電效應(yīng)及其物理機(jī)制的研究。強(qiáng)磁場和極低溫作為極端實驗條件,可以通過與電荷、自旋的相互作用改變物質(zhì)的電子結(jié)構(gòu),揭示材料的微觀性質(zhì)。但傳統(tǒng)的磁電材料測量方法并不適用于強(qiáng)磁場、極低溫這種特殊的測量環(huán)境。因此,基于脈沖強(qiáng)磁場技術(shù),我們研究設(shè)計了適用于強(qiáng)磁場、極低溫環(huán)境下的磁電效應(yīng)測量系統(tǒng),并利用所搭建的系統(tǒng)對CuFeO2單晶樣品的磁電效應(yīng)進(jìn)行了測量。本文主要內(nèi)容如下： 一、介紹了脈沖強(qiáng)磁場的研究背景和發(fā)展現(xiàn)狀。從多鐵材料入手,介紹了磁電材料與多鐵材料之間的聯(lián)系與區(qū)別�？偨Y(jié)了磁電材料中不同的磁電耦合機(jī)理以及磁電材料的研究現(xiàn)狀。在目前正在使用的幾種磁電效應(yīng)測量方法的基礎(chǔ)上,提出基于脈沖強(qiáng)磁場環(huán)境的磁電效應(yīng)測量系統(tǒng)的設(shè)計方案。 二、結(jié)合脈沖強(qiáng)磁場、低溫和電場,設(shè)計了一套基于脈沖強(qiáng)磁場的磁電效應(yīng)測量系統(tǒng)。作者對測量系統(tǒng)的各個硬件組成部分進(jìn)行了理論分析和實驗研究,并對系統(tǒng)進(jìn)行優(yōu)化。該系統(tǒng)實現(xiàn)了最高磁感應(yīng)強(qiáng)度60T、脈寬30ms的磁場環(huán)境以及2-300K連續(xù)可調(diào)的溫度環(huán)境。與傳統(tǒng)磁電效應(yīng)測量裝置相比,該系統(tǒng)磁場強(qiáng)度高,產(chǎn)生的極化電流信號強(qiáng),更容易測量。同時由于脈沖強(qiáng)磁場具有較高的磁場變化率,利用所設(shè)計的測量系統(tǒng)還可用于研究材料磁電耦合的動力學(xué)行為。 三、基于脈沖強(qiáng)磁場特性以及測量系統(tǒng)硬件指標(biāo),使用LabVIEW設(shè)計編寫了磁電效應(yīng)測量軟件,實現(xiàn)儀器的遠(yuǎn)程控制和測量。為了提高數(shù)據(jù)處理效率,設(shè)計了磁電效應(yīng)測量系統(tǒng)數(shù)據(jù)處理軟件。 四、在對所搭建的磁電效應(yīng)測量系統(tǒng)各組成部分理論分析和實驗的基礎(chǔ)上,使用CuFeO2單晶樣品對測量系統(tǒng)進(jìn)行實驗驗證。隨后利用設(shè)計的磁電效應(yīng)測量系統(tǒng),研究了CuFeO2單晶的磁電耦合行為,并通過施加不同掃描速率、不同場強(qiáng)大小的脈沖強(qiáng)磁場,對CuFeO2在不同溫度下的磁電效應(yīng)及其動力學(xué)行為進(jìn)行了系統(tǒng)研究。實驗結(jié)果證實該測量系統(tǒng)能在脈沖強(qiáng)磁場下穩(wěn)定運行,所得結(jié)果準(zhǔn)確可靠。
[Abstract]:With the development of science and technology, the demand for miniaturization of devices is getting higher and higher, so it is necessary to explore new materials with two or more functions at the same time, in order to develop new devices that can realize multiple functions at the same time. Multifunctional materials, especially magnetoelectric materials, have been widely concerned by researchers. However, the magnetoelectric coupling effect in magnetoelectric materials is generally very weak, so it is difficult to obtain effective magnetoelectric coupling signal by traditional measurement methods, which seriously affects the study of magnetoelectric effect and its physical mechanism. As extreme experimental conditions, strong magnetic field and extremely low temperature can change the electronic structure of the material through the interaction with charge and spin, and reveal the microscopic properties of the material. However, the traditional magnetoelectric material measurement method is not suitable for the special measurement environment of strong magnetic field and very low temperature. Therefore, based on the pulse strong magnetic field technology, we study and design a magnetoelectric effect measurement system suitable for high magnetic field and very low temperature environment, and use the built system to measure the magnetoelectric effect of CuFeO2 single crystal samples. The main contents of this paper are as follows: first, the research background and development status of pulse strong magnetic field are introduced. Starting with multi-iron materials, the relationship and difference between magnetoelectric materials and multi-iron materials are introduced. The different magnetoelectric coupling mechanisms and the research status of magnetoelectric materials in magnetoelectric materials are summarized. On the basis of several magnetoelectric effect measurement methods being used at present, a design scheme of magnetoelectric effect measurement system based on pulse strong magnetic field environment is proposed. Second, combined with pulse strong magnetic field, low temperature and electric field, a set of magnetoelectric effect measurement system based on pulse strong magnetic field is designed. The author makes theoretical analysis and experimental research on each hardware component of the measurement system, and optimizes the system. The system realizes the magnetic field environment with the highest magnetic induction intensity of 60T, the pulse width 30ms and the continuously adjustable temperature environment of 2 鈮，

本文編號：2492568