【摘要】：隨著信息產(chǎn)業(yè)和無線通信技術(shù)的高速發(fā)展,電子設(shè)備變得更加高度集成化、多功能化和小型化。Kneller在1990年提出交換耦合機(jī)制后,永磁復(fù)合材料的研究主要集中在金屬永磁復(fù)合材料,例如Nd-Fe-B和Sm-Co等,盡管其磁能積BH(max)相對(duì)于單相永磁材料有了大幅提高,但是由于成本高且不耐腐蝕,限制了金屬永磁復(fù)合材料在工業(yè)生產(chǎn)中的應(yīng)用。相比金屬永磁復(fù)合材料,利用交換耦合原理制備的鐵氧體永磁復(fù)合材料,不僅具有較高的剩磁(Br)、矯頑力(Hc)和磁能積BH(max)而且成本低、合成制備方法簡(jiǎn)單耐腐蝕性好。本論文選擇M型鋇鐵氧體(Ba Fe12O19)為硬磁相,鐵酸鈷(Co Fe2O4)和釔鐵石榴石(Y3Fe5O12)分別為軟磁相,采用溶膠-凝膠法制備永磁復(fù)合粉體,并通過微波燒結(jié)法獲得永磁復(fù)合陶瓷。運(yùn)用X射線衍射儀(XRD)、顯微共焦激光拉曼光譜儀(Raman Spectra)、掃描電子顯微鏡(SEM)、透射電子顯微鏡(TEM)對(duì)試樣的物相及化學(xué)組成和微觀形貌進(jìn)行分析;用精密阻抗分析儀和振動(dòng)樣品磁強(qiáng)計(jì)(VSM)對(duì)其介電和磁性能進(jìn)行分析研究;用矢量網(wǎng)絡(luò)分析儀對(duì)磁性復(fù)合粉體吸波性能進(jìn)行測(cè)試研究,并對(duì)復(fù)合材料制備工藝和形成機(jī)理進(jìn)行研究。該實(shí)驗(yàn)包括以下部分:(1)首先,采用溶膠-凝膠法制備Ba Fe12O19/Co Fe2O4永磁復(fù)合粉體,研究煅燒溫度、螯合劑、p H值以及不同Co Fe2O4含量對(duì)永磁復(fù)合粉體物相組成的綜合影響。其次,采用微波燒結(jié)法,成功制備出Ba Fe12O19/Co Fe2O4永磁復(fù)合陶瓷。實(shí)驗(yàn)結(jié)果表明,復(fù)合陶瓷物相組成清晰,晶粒分布均勻、燒結(jié)致密。通過研究Ba Fe12O19/Co Fe2O4永磁復(fù)合粉體磁滯回線,可以發(fā)現(xiàn)永磁復(fù)合粉體兩相之間具有優(yōu)異的交換耦合性。相比于純相粉體材料,永磁復(fù)合粉體的飽和磁化強(qiáng)度和剩余磁化強(qiáng)度均有所提高,當(dāng)Co Fe2O4含量達(dá)到10%時(shí),永磁復(fù)合粉體的磁能積相比于純相Ba Fe12O19提高了10%。通過對(duì)該材料吸波性能的研究發(fā)現(xiàn),Co Fe2O4含量達(dá)到10%時(shí),復(fù)合材料體系在17.66GHz出現(xiàn)了最大吸收峰-15.69 d B。此外,在13.2~18.17 GHz范圍內(nèi),永磁復(fù)合粉體材料的吸收峰,始終大于純相Ba Fe12O19的吸收峰。實(shí)驗(yàn)還對(duì)相應(yīng)的燒結(jié)陶瓷材料的磁學(xué)性能及介電性能進(jìn)行研究。研究表明,隨著Co Fe2O4含量的增加,永磁復(fù)合陶瓷的飽和磁化強(qiáng)度以及剩余磁化強(qiáng)度均明顯增大,而其介電常數(shù)有所下降,介電損耗角正切值(tan?)先增大后減小。(2)通過采用溶膠-凝膠法制備Ba Fe12O19/Y3Fe5O12永磁復(fù)合粉體,研究煅燒溫度、螯合劑和p H值以及不同Y3Fe5O12含量對(duì)永磁復(fù)合粉體物相的影響。隨后,應(yīng)用微波燒結(jié)法將上述實(shí)驗(yàn)所得永磁復(fù)合粉體進(jìn)行燒結(jié),制備出Ba Fe12O19/Y3Fe5O12永磁復(fù)合陶瓷。實(shí)驗(yàn)結(jié)果表明,復(fù)合陶瓷兩相之間分布均勻,化學(xué)相容性好。通過研究Ba Fe12O19/Y3Fe5O12永磁復(fù)合粉體磁滯回線,發(fā)現(xiàn)永磁復(fù)合粉體的兩相之間具有優(yōu)異的交換耦合性。相比于純相粉體,永磁復(fù)合粉體的矯頑場(chǎng)和剩余磁化強(qiáng)度均有所提高,當(dāng)Y3Fe5O12含量達(dá)到10%時(shí),永磁復(fù)合粉體的磁能積為純相Ba Fe12O19的2倍。通過對(duì)該材料吸波曲線的研究,當(dāng)Y3Fe5O12含量達(dá)到10%時(shí),在19.66 GHz出現(xiàn)了最大吸收峰-17.51 d B,吸收大于-8.47 GHz(Y3Fe5O12)的峰寬達(dá)到4.3 GHz,表明該組分粉體具有優(yōu)異的吸波性能。在對(duì)燒結(jié)陶瓷材料的磁學(xué)性能及介電性能研究過程中,測(cè)試結(jié)果表明,隨著Y3Fe5O12含量的增加,永磁復(fù)合陶瓷的矯頑場(chǎng)和剩余磁化強(qiáng)度增大,介電常數(shù)和介電損耗角正切值(tan?)均減小。
[Abstract]:With the rapid development of information industry and wireless communication technology, electronic devices have become more integrated, multifunctional and miniaturized. After Kneller proposed the exchange coupling mechanism in 1990, the research on permanent magnet composites has focused on metal permanent magnet composites, such as Nd-Fe-B and Sm-Co, although their magnetic energy product BH (max) is relative to single-phase. Permanent magnet materials have been greatly improved, but the high cost and non-corrosion resistance limit the application of metal permanent magnet composites in industrial production. Compared with metal permanent magnet composites, ferrite permanent magnet composites based on exchange coupling principle have not only higher remanence (Br), coercivity (Hc) and magnetic energy product BH (max), but also higher cost. In this paper, M-type barium ferrite (Ba Fe12O19) was chosen as hard magnetic phase, cobalt ferrite (Co Fe2O4) and yttrium iron garnet (Y3Fe5O12) as soft magnetic phase, and permanent magnet composite powders were prepared by sol-gel method. The composite ceramics were obtained by microwave sintering. X-ray diffractometer (XRD) and micro-copolymer were used. Raman Spectra, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to analyze the phase, chemical composition and micro-morphology of the samples, the dielectric and magnetic properties of the samples were analyzed by precision impedance analyzer and vibrating sample magnetometer (VSM), and the magnetic composite powder was absorbed by vector network analyzer. The experiment includes the following parts: (1) Firstly, Ba Fe12O19/Co Fe2O4 permanent magnet composite powders were prepared by sol-gel method. The effects of calcination temperature, chelating agent, P H value and different content of Co Fe2O4 on the phase composition of the composite powders were studied. Secondly, Ba Fe12O19/Co Fe2O4 permanent magnet composite ceramics were successfully prepared by microwave sintering. The experimental results show that the composite ceramics have clear phase composition, uniform grain distribution and compact sintering. By studying the hysteresis loops of Ba Fe12O19/Co Fe2O4 permanent magnet composite powders, excellent exchange coupling between the two phases can be found. The saturation magnetization and remanence magnetization of the composite powders were improved by 10% when the content of Co-Fe_2O_4 reached 10%, and the magnetic energy product of the composite powders was 10% higher than that of the pure phase Ba-Fe_12O_19. In addition, the absorption peak of the composite powders was always larger than that of the pure phase Ba Fe12O19 in the range of 13.2-18.17 GHz. The magnetic and dielectric properties of the sintered ceramics were also studied experimentally. The results show that with the increase of Co Fe2O4 content, the absorption peak of the composite ceramics is always larger than that of the pure phase Ba Fe12O19. The saturated magnetization and residual magnetization of Ba Fe12O19/Y3Fe5O12 composite powders were increased obviously, while the dielectric constant decreased, and the tangent value of dielectric loss angle (tan?) increased first and then decreased. (2) The effects of calcination temperature, chelating agent and P H value and Y3Fe5O12 content on the properties of Ba Fe12O19/Y3Fe5O12 composite powders were studied by sol-gel method. Afterwards, Ba Fe12O19/Y3Fe5O12 permanent magnet composite ceramics were prepared by microwave sintering method. The experimental results show that the two phases of the composite ceramics are uniformly distributed and have good chemical compatibility. The coercive field and residual magnetization of the composite powders are improved compared with those of pure phase powders. When the content of Y3Fe5O12 reaches 10%, the magnetic energy product of the composite powders is twice that of pure phase Ba Fe12O19. The maximum absorption peak appeared at 19.66 GHz - 17.51 D B, and the peak width of absorption larger than - 8.47 GHz (Y3Fe5O12) reached 4.3 GHz, indicating that the composite powder had excellent absorbing properties. During the study of magnetic and dielectric properties of sintered ceramics, the coercive field of permanent magnet composite ceramics increased with the increase of Y3Fe5O12 content. The dielectric constant and dielectric loss tangent (tan?) decrease with the increase of residual magnetization.
【學(xué)位授予單位】：陜西科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TM277;TB33

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 何才君;霍德璇;李曉光;呂燕飛;趙士超;;BaFe_(12-x)(Ni_(0.5)Cu_(0.5)Zr)_(x/2)O_(19)/聚苯胺復(fù)合材料的吸波性能[J];材料科學(xué)與工程學(xué)報(bào);2010年03期

2 Hamid Zaigham;F.Ahmad Khalid;;Exchange Coupling and Magnetic Behavior of SmCo_(5-x)Sn_x Alloys[J];Journal of Materials Science & Technology;2011年03期

3 都有為;;磁性材料新近進(jìn)展[J];物理;2006年09期

4 趙靈智;胡社軍;李偉善;何琴玉;陳俊芳;汝強(qiáng);;吸波材料的吸波原理及其研究進(jìn)展[J];現(xiàn)代防御技術(shù);2007年01期

相關(guān)博士學(xué)位論文 前2條

1 劉穎;摻雜M-型鋇鐵氧體的制備及磁學(xué)性能研究[D];哈爾濱工程大學(xué);2007年

2 何驚華;鐵氧體基復(fù)合系統(tǒng)磁性及交換偏置[D];華中科技大學(xué);2009年

相關(guān)碩士學(xué)位論文 前4條

1 程春浩;高性能M型鍶鐵氧體的磁性研究[D];安徽大學(xué);2012年

2 范瑞;BaFe_(12)O_(19)/ZnFe_2O_4磁性納米復(fù)合材料制備與性能研究[D];蘭州理工大學(xué);2013年

3 張鵬;聚苯胺基鈷鐵復(fù)合吸波材料的制備及吸波性能[D];哈爾濱工業(yè)大學(xué);2013年

4 蔣博;鋇鐵氧體磁性材料的制備及吸波性能的研究[D];中北大學(xué);2014年

，

本文編號(hào)：2201098