La_（1-x）（K_x、Ag_x）MnO_3体系的微波吸收特性研究
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摘要
掺杂稀土锰氧化物因其巨磁电阻效应和奇异的电磁特性,多年来一直是磁电子功能材料领域的一个研究热点。因为其特殊的电磁性能,这类材料可能成为一类新型微波吸收材料,但有关报道少见。本文研究了A位分别掺K和Ag的LaMnO3体系的微波吸收特性。
用溶胶-凝胶法制备了La1-xKxMnO3和La1-xAgxMnO3纳米粉体,用DSC-TG、EDS、XRD、SEM对样品的形成过程、成分、晶体结构、微观形貌进行了系列表征分析。研究结果表明,样品的形成过程分为吸附水蒸发、EDTA分解、硝酸根离子分解以及钙钛矿晶型的形成等阶段；La1-XKxMnO3和La1-xAgxMnO3纳米粉体晶体结构均为钙钛矿型,且随着掺杂量增加和温度的升高,样品中均有少量杂相出现。两种样品的颗粒形貌均呈不规则椭球状或短棒状,La1-xKxMnO3和La1-xAgxMnO3样品颗粒平均粒径分别约60nm和100nm。
用微波网络分析仪测试了La1-xKxMnO3和La1-xAgxMn03在2-18GHz频率范围内的复介电常数和复磁导率,计算了样品在该频率范围的微波反射率和电磁损耗角正切,分析了掺杂量和样品厚度对体系微波吸收性能的影响及微波损耗机制。结果表明,x=0.3时,厚度2.40mm的La1-XKxMnO3在9.9GHz位置处吸收峰值为27.1dB,大于10dB频宽为10.6GHz; x=0.15时,厚度2.60mm的La1-x AgxMnO3在12.0GHz处吸收峰值为24.9dB,大于10dB频宽为7.1GHzo
La1-xKxMnO3和La1-xAgxMnO3样品兼具介电损耗和磁损耗,但介电损耗相对较强。两种损耗角正切随微波频率的变化相反,可能是基体中铁磁与反铁磁团簇在微波电磁场作用下相互转变或竞争引起。
Doped rare-earth manganeties have been becoming a hot and active topic in the field of magnet-electron functional materials because of their giant magnetoresistance effect and special electromagnetic properties over the years.Owing to the properties, it's possible that such materials become a new type of microwave absorbing materials, but few are reported. The microwave absorbing properties of LaMnO3 system doped by K and Ag at A site respectively were studied in this thesis.
The nano-crystalline powder samples of La1-xKxMnO3and La1-xAgxMn03 were prepared by sol-gel method.The formation, composition, crystal structure and particle morphology of these samples were characterized by DSC-TGA,EDS,XRD,SEM. The results showed that the formation of the samples were consist of water evaporation EDTA decomposition, nitrate decomposition and perovskite crystalline growth. Both the crystal structure of La1-xKxMnO3nanocrystalline powders and La1-xAgxMn03 were perovskite type, and A small amount of impurity phase appeared in the samples with the increasing of doping components and temperature. Their crystal powder morphology was irregular ellipsoidal shape or short rod, and the average size of La1-xKxMn03 sample particles was about 60nm and La1-xAgxMn03 about 100nm.
Their complex permittivity and complex permeability were measured by microwave vector network analyzer in the frequency range from 2 to 18 GHz, and the reflection coefficient and loss tangent were calculated according to measurements. The effects of doping and thickness on microwave absorption of them and the microwav loss mechanism were discussed. The results showed that the absorption peak of Lai-xKxMn03 with 2.20 mm thickness (x= 0.3) was 27.1dB at 9.9GHz and its bandwidth above lOdB was 10.6GHz,and Lai-xAgxMn03 with 2.60 mm thickness (x=0.15) was 24.9dB at 12.0GHz and bandwidth 7.1 GHz.
They had both dielectric loss and magnetic loss, but the former is relatively stronger.lt was possibly caused by a mutual transformation or competetion between ferromagnetic and antiferromagnetic clusters of the matrix in the microwave electromagnetic field that magnetic and dielectric loss tangent changed inversely with the changes of microwave frequency.
用溶胶-凝胶法制备了La1-xKxMnO3和La1-xAgxMnO3纳米粉体,用DSC-TG、EDS、XRD、SEM对样品的形成过程、成分、晶体结构、微观形貌进行了系列表征分析。研究结果表明,样品的形成过程分为吸附水蒸发、EDTA分解、硝酸根离子分解以及钙钛矿晶型的形成等阶段；La1-XKxMnO3和La1-xAgxMnO3纳米粉体晶体结构均为钙钛矿型,且随着掺杂量增加和温度的升高,样品中均有少量杂相出现。两种样品的颗粒形貌均呈不规则椭球状或短棒状,La1-xKxMnO3和La1-xAgxMnO3样品颗粒平均粒径分别约60nm和100nm。
用微波网络分析仪测试了La1-xKxMnO3和La1-xAgxMn03在2-18GHz频率范围内的复介电常数和复磁导率,计算了样品在该频率范围的微波反射率和电磁损耗角正切,分析了掺杂量和样品厚度对体系微波吸收性能的影响及微波损耗机制。结果表明,x=0.3时,厚度2.40mm的La1-XKxMnO3在9.9GHz位置处吸收峰值为27.1dB,大于10dB频宽为10.6GHz; x=0.15时,厚度2.60mm的La1-x AgxMnO3在12.0GHz处吸收峰值为24.9dB,大于10dB频宽为7.1GHzo
La1-xKxMnO3和La1-xAgxMnO3样品兼具介电损耗和磁损耗,但介电损耗相对较强。两种损耗角正切随微波频率的变化相反,可能是基体中铁磁与反铁磁团簇在微波电磁场作用下相互转变或竞争引起。
Doped rare-earth manganeties have been becoming a hot and active topic in the field of magnet-electron functional materials because of their giant magnetoresistance effect and special electromagnetic properties over the years.Owing to the properties, it's possible that such materials become a new type of microwave absorbing materials, but few are reported. The microwave absorbing properties of LaMnO3 system doped by K and Ag at A site respectively were studied in this thesis.
The nano-crystalline powder samples of La1-xKxMnO3and La1-xAgxMn03 were prepared by sol-gel method.The formation, composition, crystal structure and particle morphology of these samples were characterized by DSC-TGA,EDS,XRD,SEM. The results showed that the formation of the samples were consist of water evaporation EDTA decomposition, nitrate decomposition and perovskite crystalline growth. Both the crystal structure of La1-xKxMnO3nanocrystalline powders and La1-xAgxMn03 were perovskite type, and A small amount of impurity phase appeared in the samples with the increasing of doping components and temperature. Their crystal powder morphology was irregular ellipsoidal shape or short rod, and the average size of La1-xKxMn03 sample particles was about 60nm and La1-xAgxMn03 about 100nm.
Their complex permittivity and complex permeability were measured by microwave vector network analyzer in the frequency range from 2 to 18 GHz, and the reflection coefficient and loss tangent were calculated according to measurements. The effects of doping and thickness on microwave absorption of them and the microwav loss mechanism were discussed. The results showed that the absorption peak of Lai-xKxMn03 with 2.20 mm thickness (x= 0.3) was 27.1dB at 9.9GHz and its bandwidth above lOdB was 10.6GHz,and Lai-xAgxMn03 with 2.60 mm thickness (x=0.15) was 24.9dB at 12.0GHz and bandwidth 7.1 GHz.
They had both dielectric loss and magnetic loss, but the former is relatively stronger.lt was possibly caused by a mutual transformation or competetion between ferromagnetic and antiferromagnetic clusters of the matrix in the microwave electromagnetic field that magnetic and dielectric loss tangent changed inversely with the changes of microwave frequency.
引文
[1]康青.新型微波吸收材料.北京：科学出版社,2006,34～66,303～304.
[2]黄娟娟.片状磁性金属及合金纳米颗粒的微波磁性与微波吸收特性研究.兰州：兰州大学,2007.
[3]邢丽英.隐身材料.北京：化学工业出版社.2004,41～46.
[4]廖绍彬.铁磁学(下册).北京：科学出版社,2000,1～60.
[5]阮颖铮.雷达散射截面与隐身技术.北京：国防工业出版社,1998,269～27
[6]周馨我.功能材料学[M].北京：北京理工大学出版社,2002,237～241.
[7]胡传忻.隐身涂层技术.北京：化学工业出版社,2004,194～200.
[8]徐文兰,沈学础.隐身技术和物理.物理,1995,24(5)：29～295.
[9]Shams M H,Salehi S M A,Ghasemi A.Electromagnetic wave absorption characteristics of Mg-Ti substituted Ba-hexaferrite. Mater. Lett,2008,62: 1731～1733.
[10]Singh P,Babbar V K,Razdan A,et al.Complex permittivity, permeability, and x-band microwave avsorption of CaCoTi.ferrite. composites.J.Appl. Phys.2000,87(9):4362～4365.
[11]何华辉,熊波,聂彦.含FSS的双层吸波材料吸波性能的MathCAD计算模拟.磁性材料及器件,2006,37(1)：13～28.
[12]方俊鑫,殷之文.电解质物理学.北京：科学出版社,1989.16-82.
[13]周克省,黄可龙,孔德明等.吸波材料的物理机制及其设计.中南工业大学学报.2001,32(6)：617～621.
[14]姜寿亭,李卫.凝聚态磁性物理.北京：科学出版社,2003.10.378～417.
[15]周克省,黄可龙,尹荔松,孔德明.纳米无机物/聚合物复合吸波功能材料.高分子材料科学与工程,2002,18(3)：15-19.
[16]方俊鑫,陆栋.固体物理学(下册).上海：上海科学技术出版社,1981.66～238.
[17]闻立时,黄荣芳,刘得成等.纳米结构电磁工程微观原理研究.真空,200(4)：1～9.
[18]戴道生,熊光成,吴思诚.RE1-xTxMnO3氧化物的结构、电磁特性和巨磁电阻.物理学进展,1997,17(2)：201～222.
[19]刘俊明,王克锋.稀土掺杂锰氧化物庞磁电阻效应.物理学进展,2005,25(1)：82～130.
[20]陈慧兰.高等无机化学.北京：高等教育出版社,2005,112～119,336～337.
[21]Mukovskii Y,Arkhipov V,Arsenov A,et al.Magnetic and transport prope rties of perfect La0.8Ba0.2MnO3 single crystal.J.Alloys.Compd.2001,326:1 08-111.
[22]Waollan E O,Koehler W C.Neutron diffraction study of the magnetic properties of the series of perovskite-type compounds[(1-x)La, xCa]Mn03. Phys.Rev,1955,100(2):545～563.
[23]Jonker G H.Magnetic compounds with perovskite structure.Physica,1956, 22:707～722.
[24]Gennes P.Effects of Double Exchange in Magnetic Crystals.Phys.Rev,19 60,118(1):141 ～154.
[25]Matsumoto G.Study of (La1-xCax)MnO3 I Magnetic structure of LaMnO 3.J.Phys Soc Jpn,1970,29(3):606～615.
[26]Imamori S,Tokunaga M,Hakuta S,et al.Room temperature low-field colo ssal magnetoresistance in La0.7Sro.3MnO3.Appl.Phys.Lett.2006,89:172508-1～3.
[27]Srinivasu V V,Lofland S E,Bhagat S M.Room temperature colossal mi crowave magnetoimpedance in micron-sizepowders of La0.7Ba0.3Mn03 a nd La0.7Sro.3Mn03-A novel magnetic tape..J.Appl.Phys.1998,83(5):2866～ 2868.
[28]Ye S L,Song W H,Dai J M,et al.Large room temperature magnetresista nee and phase separation in La1-xNaxMn03 with 0.1 [29]陈永虔诚,谷坤明,唐涛.掺K+和Ag+的LaMnO3的室温庞磁电阻效应.磁性材料及器件,2001,32(3)：9～13.
[30]Salamon M B,Jaime M.The physics of manganites:Structure and trans port.Rev.Mod.Phys,2001,73(3):583～628.
[31]Phan M H,Tho N D,Chau N,et al.Large magnetic entropy change abov e 300K in a colossal magnetoresistive material La0.7Sro.3Mn0.98Nio.02O3. J.Appl.Phys,2005,97:103901-1～5.
[32]Zener C.Interaction between the d-shells in the transition metals ferrom agnetic compounds of manganese with perovskite structure.Phys.Rev,19 50,82(3):403～405.
[33]Schlottmann P.Phase diagram and spin-canting effects in electron-doped LaMnO3.Phys.Rev.B,2008,77:104446-1-7.
[34]Eom T W,Hyun Y H,Park J S,Lee Y P,Prokhorov V G.,Flis V S,Svetc hnikoV L v.Griffiths phase and charge ordering in electron-doped La0.9 Ce0.1MnO3 films.Appl.Phys.Lett.2009,94:152502-1-3.
[35]Fuchs D,Schweiss P,Adelmann P,et al.Ferro-magnetic order in the electr on-doped system La,-xCexCoO3.Phys.Rev.B 2005,72:014466-1～4.
[36]Wang D J,Sun J R,Zhang S Y,Liu G J,Shen B G.Hall effect in Lao.7C eo.3MnO3+δ films with variable oxygen content.Phys.Rev.B,2006,73:1444 03-1-6.
[37]Boudayay C,Laroussiy L,Dhahriy E,et al.Magnetic and magnetoresistanc e properties in rhombohedral La1-xK+xMn03 perovskite-type compounds. J.Phys.Condens.Matter,1998,(10):7485-7492.
[38]Prokhorov V. G.,Kaminsky G. G.,Flis V S,Hyun Y H,Park S Y,and Lee Y PSvetchnikov V L.Magnetic ordering and charge transport in electr on-doped La,-yCeyMnO3 (0.1≤ y≤ 0.3)Films. Low Temp. Phys.2009, 35(6):468-475.
[39]Krishnamoorthy C,Sethupathi K,Sankaranarayanan V,Nirmala R,Malik S K.Magnetic and magnetotransport properties of Ce doped LaMnO3.Jou rnal of Alloys and Compounds,2007,438:1-7.
[40]Mina B I.,Kwona S K,Leeb B W,Kang J-S.Electronic structures of ele ctron-doped manganite:La0.7Ce0.3MnO3 Journal of Electron Spectroscop y and Related Phenomena 114-116(2001)801-805.
[41]Bajaj Kavita,Jesudasan John,Bagwe Vivas,CKothari D,Pratap Raychaudh uri. Correlation between effects of electric current and magnetic field on transport properties of electron-doped manganite La0.7Ce0.3MnO3 thi n films.J.Phys.Condens.Matter,2007,19:382202-1-8.
[42]Gayone J E,Abbate M,Alejandro G.,Lamas D G.,Tovar M,Zampieri G.. Ce valence in La0.47Ce0.20Ca0.33Mn03.Journal of Alloys and Compounds ,2004,369:252-255.
[43]Das S,Poddar A,Roy B,Giri S.Studies of transport and magnetic proper ties of Ce-doped LaMno3.Journal of Alloys and Compounds,2004,365:9 4-101.
[44]Philip J,Kutty T R N.Effect of valence fluctuations in A sites on the t ransport properties of La1-xRxMnO3 (R=Ce,Pr).J.Phys.:Condens. Matter,1 999,11:8537～8546.
[45]Chang W J,Tsai J Y,Jeng H T,et al.Electronic structure and transport p roperties of La0.7Ce0.3MnO3.Phys.Rev.B,2005,72:132410-1-4.
[46]Manjunath B,Bellakki C,Shivakumara N Y,Vasanthacharya A S.Prakash Rapid synthesis of room temperature ferromagnetic Ag-doped LaMnO3 perovskite phases by the solution combustion method Materials Resea rch Bulletin 45(2010)1685-1691.
[47]Laiho R K,Lisunov G.,Lahderanta E,et al.Influence of the phase separat ion effect on low-field magnetic properties of Lai1-xBaxMnO3.J.Magn.Ma gn.Mater.,2005,293:892-902.
[48]胡季帆,梅良模,丁志强.钙钛矿氧化物(Ca, Ba)0.35Mn1-xFexOy的磁电阻效应.稀土,2000,21(1)：19-22.
[49]Cai J W,Wang C,Shen B G.et al.Colossal magnetoresistance of spin-gla ss perovskite La0.67Ca0.33Mn0.9Fe0.1O3.Appl.Phys.Lett.1997,71 (12):1727-1 729.
[50]Bhame S D,Joseph Joly V. L, Joy P A.Effect of disorder on the magn etic properties of LaMn0.5Fe0.5O3.Phys.Rev.B,2005,72:054426-1-7.
[51]Karmakar S,Taran S,Chaudhuri B K,et al.Disorder-induced short-range f erromagnetism and cluster spin-glass state in sol-gel derived La0.7Ca0.3 Mn1-xCdxO3(0≤x≤0.2).Phys.Rev.B,2006,74:104407-1-10.
[52]Kirilyuk A,Demyk K,Helden G.,Meijer G..et al.Atomic clusters of magn etic oxides:Structure and phonons. J.Appl.Phys.,2003,93(10):7379-738 1.
[53]Manjunath B,Bellakki C,Shivakumara N Y,Vasanthacharya A S. Prakash. Rapid synthesis of room temperature ferromagnetic Ag-doped LaMnO 3 perovskite phases by the solution combustion method.Materials Resea rch Bulletin,2010,45:1685-1691.
[54]Bera A K,Yusuf S M.Ferromagnetic clusters in the Brownmillerite bila yered compounds Ca2.5-xLaxSr0.5GaMn2O8 An approach to achieve layer ed spintronics materials.Jourl of Appled Physics,2010,107:013911-1-4.
[55]Samal D,Shivakumara C,Anil Kumar P S.The incongruous observation of magnetic phase separation in La0.85Sr0.15CoO3 spin glass system. Jou r1 of Appled Physics,2009,106:123920-1-8.
[56]Tang Y K,Ma X,Kou Z Q,et al.Slight La doping induced ferromagneti c clusters in layered La3-3xSri+3xMn3O10(x=1.00,0.99,0.95).Phys.Rev.B,20 05,72:132403-1-4.
[57]Autret C,Martin C,Rotoux R,et al.Coexistance of ferromagnetism and a ntiferromagnetism in the La0.08Ca1.92-MnO4 series. J.Magn.Magn. Mater.2 004,284:172-180.
[58]Chatterjee S,Giri S,Majumdar S.Metastability around the insulator-metal transition in La0.2Pr0.5Ca0.3MnO3. Jourl of Appled Physics,2010,107:11 3909-1-5.
[59]Huang X H,Ding J F,Jiang Z L,Yin Y W,Yu Q X,Li X G.Dynamic pr operties of cluster glass in La0.25Ca0.75MnO3 nanoparticles.Jourl of Appl ed Physics,2009,106:083904-1-5.
[60]Geetha Kumary T,Lin J G.,Valsakumar M C.Magnetic phase separation in Ndo.5(Ca,Sr)0.5Mn03. Jourl of Appled Physics,2010,108:043922-1-4.
[61]Jonker G H,Van Santen J H.Ferromagnetic compounds of manganese with perovskite structure. Physica,1950,16:337-348.
[62]Urushibara A,Moritomo Y,Aima T,et al.Insulator-metal transition and gi ant magnetoresistance in Lai.xSrxMnO3.Phys.Rev.B,1995,51(20):14103-1 4109.
[63]Imamorid S,Tokunaga M,Hakuta S,et al.Room temperatuer low-field col ossal magnetoresistance in Lao 7Sro.3MnO3.Appl.Phys.Lett.,2006,89:17250 8-1-3.
[64]Parmar R N,Markna J H,Kuberkar D G..Swift-heave-ion-irradiation-indu ced enhancement in electrical conductivity of chemical solution deposit ed Lao.7Bao.3Mn03 thin films. Appl.Phys.Lett.,2006,89:202506-1-3.
[65]Ang R,Lu W J,Zhang R L,et al.Effects of Co doping bilayered manga nite LaSr2Mn2O7:Resistivity,themoelectric power and thermal conductivit y. Phys. Rev.B,2005,72:184417-1-8.
[66]Neupane K P,Cohn J L,Terashita H.,et al.Doping dependence of polaro n hopping energies in La1-xCaxMnO3(0 [67]Srinivasu V V,Lofland S E,Bhagat S Met al.Temperature and field de pendence of microwave losses in manganite powders.J. Appl. Phys.199 9,86(2):1067-1072.
[68]Owens F J.Giant magneto radio frequency absorption in magnetoresisti ve ma-terials Lao.7(Sr,Ca)0.3MnO3.J. Appl. Phys.1997,82(6):3054-3057.
[69]Patil S Ⅰ,Lofland S E,Shu Q Q,et al.Half-pointfields for microwave ma g-netoabsorption in colossal magneto-resistance manganite powders. J. Appl. Phys.,2000,87(5):2652-2654.
[70]Rivas-Murias B R,Ramos C A,Senaris-Rodriguez M A,et al.Non-resona nt microwave absorption in Pr1-xBaxCoO3-δ. J. Magn.Magn.Mater.2004, 272-276:e1635-e1636.
[71]Huhtinen H,Laiho R,Vlasenko L S,et al.Effect of illumination on mag-netization and microwave absorption of La1-xCaxMn03 (x<0.2) films. J.Magn.Magn.Mater.2008,320(11):1747-1752.
[72]Li G,Hu G. QZhou H D,et al.Attractive microwave-absorbing propertie s of La1-xSrxMnO3.Mater.Chem.Phys.,2002,75(1):101-104.
[73]胡国光,尹萍,吕庆荣.La1-xSrxMnO3微波吸收特性的研究.磁性材料及器件,2000,3 1(6)：14～17.
[74]胡国光,尹萍,吕庆荣.La1-xSrxMnO3氧化物的导电和吸收特性.中国稀土学报,2002,20(2)：179～180.
[75]孙杰,刘建华,李松梅.La0.5Sr0.5MnO3纳米晶体的制备与电磁性能研究.稀有金属材料与工程,2005,34(11)：1814～1817.
[76]Yang R B,Tsay C Y,Liang W F,Lin C K.Microwave absorbing properti es of La0.7Sr0.3Mn03 composites with negative magnetic susceptibility [J]. J. Appl. Phys.2010,107:09A523-1-3.
[77]Tsay C Y,Yang R B,Hung D S,Hung Y H,Yaoand Y D,Lin C K.Invest igation on electromagnetic and microwave absorbing properties of La0.7 Sr0.3MnO3 carbon nanotube composites [J]J. Appl. Phys.2010,107:09A5 02-1-3.
[78]Yulan Cheng,Jianming Dai,Xuebin Zhu,Dajun Wu,Yuping Sun.Preparatio n magnetic and microwave absorption properties of La0.5Sro.sMnO3/La (OH)3 composites.Materials Research Bulletin,2010,45:663-667
[79]Zhou K-S,Xia H,Huang K-L,et al.The microwave absorption properties of Lao.8Sr0.2Mn1-yFey03 nano-crystalline powders in frequency range o f 2-18GHz.Phyica B,2009,404:175-179.
[80]ZHOU Ke-sheng, DENG Jian-jie, YIN Li-song,et al.The microwave ab sorption properties of La0.8Bao.2MnO3, Trans.Nonferrous Met. Soc. Chin a,2007,17(5):947-950.
[81]周克省,刘宝刚,黄可龙,尹荔松. Lao.6Ceo.4Mn1-yFeyO3微波吸收特性.中国稀 土学报,2009,27(1)：81-85
[82]张立德.纳米材料与纳米结构[M].北京：科学出版社,2001,51-66,322-338.
[83]Tao T,Cao Q Q,Cu K M,Xu H Y,Zhang S Y,and Du Y W.Giant magn etoresistance of the La1-xAgxMn03 polycrystalline inhomogeneous granu lar system. Appl.Phys Lett.2000,77:723-725.
[84]王广涛,张敏平,尚学府.La1-xAgxtMnO3和La1-xNaxMnO3的对比研究.低温物理学报.2005,27(1)：67～73.
[2]黄娟娟.片状磁性金属及合金纳米颗粒的微波磁性与微波吸收特性研究.兰州：兰州大学,2007.
[3]邢丽英.隐身材料.北京：化学工业出版社.2004,41～46.
[4]廖绍彬.铁磁学(下册).北京：科学出版社,2000,1～60.
[5]阮颖铮.雷达散射截面与隐身技术.北京：国防工业出版社,1998,269～27
[6]周馨我.功能材料学[M].北京：北京理工大学出版社,2002,237～241.
[7]胡传忻.隐身涂层技术.北京：化学工业出版社,2004,194～200.
[8]徐文兰,沈学础.隐身技术和物理.物理,1995,24(5)：29～295.
[9]Shams M H,Salehi S M A,Ghasemi A.Electromagnetic wave absorption characteristics of Mg-Ti substituted Ba-hexaferrite. Mater. Lett,2008,62: 1731～1733.
[10]Singh P,Babbar V K,Razdan A,et al.Complex permittivity, permeability, and x-band microwave avsorption of CaCoTi.ferrite. composites.J.Appl. Phys.2000,87(9):4362～4365.
[11]何华辉,熊波,聂彦.含FSS的双层吸波材料吸波性能的MathCAD计算模拟.磁性材料及器件,2006,37(1)：13～28.
[12]方俊鑫,殷之文.电解质物理学.北京：科学出版社,1989.16-82.
[13]周克省,黄可龙,孔德明等.吸波材料的物理机制及其设计.中南工业大学学报.2001,32(6)：617～621.
[14]姜寿亭,李卫.凝聚态磁性物理.北京：科学出版社,2003.10.378～417.
[15]周克省,黄可龙,尹荔松,孔德明.纳米无机物/聚合物复合吸波功能材料.高分子材料科学与工程,2002,18(3)：15-19.
[16]方俊鑫,陆栋.固体物理学(下册).上海：上海科学技术出版社,1981.66～238.
[17]闻立时,黄荣芳,刘得成等.纳米结构电磁工程微观原理研究.真空,200(4)：1～9.
[18]戴道生,熊光成,吴思诚.RE1-xTxMnO3氧化物的结构、电磁特性和巨磁电阻.物理学进展,1997,17(2)：201～222.
[19]刘俊明,王克锋.稀土掺杂锰氧化物庞磁电阻效应.物理学进展,2005,25(1)：82～130.
[20]陈慧兰.高等无机化学.北京：高等教育出版社,2005,112～119,336～337.
[21]Mukovskii Y,Arkhipov V,Arsenov A,et al.Magnetic and transport prope rties of perfect La0.8Ba0.2MnO3 single crystal.J.Alloys.Compd.2001,326:1 08-111.
[22]Waollan E O,Koehler W C.Neutron diffraction study of the magnetic properties of the series of perovskite-type compounds[(1-x)La, xCa]Mn03. Phys.Rev,1955,100(2):545～563.
[23]Jonker G H.Magnetic compounds with perovskite structure.Physica,1956, 22:707～722.
[24]Gennes P.Effects of Double Exchange in Magnetic Crystals.Phys.Rev,19 60,118(1):141 ～154.
[25]Matsumoto G.Study of (La1-xCax)MnO3 I Magnetic structure of LaMnO 3.J.Phys Soc Jpn,1970,29(3):606～615.
[26]Imamori S,Tokunaga M,Hakuta S,et al.Room temperature low-field colo ssal magnetoresistance in La0.7Sro.3MnO3.Appl.Phys.Lett.2006,89:172508-1～3.
[27]Srinivasu V V,Lofland S E,Bhagat S M.Room temperature colossal mi crowave magnetoimpedance in micron-sizepowders of La0.7Ba0.3Mn03 a nd La0.7Sro.3Mn03-A novel magnetic tape..J.Appl.Phys.1998,83(5):2866～ 2868.
[28]Ye S L,Song W H,Dai J M,et al.Large room temperature magnetresista nee and phase separation in La1-xNaxMn03 with 0.1
[30]Salamon M B,Jaime M.The physics of manganites:Structure and trans port.Rev.Mod.Phys,2001,73(3):583～628.
[31]Phan M H,Tho N D,Chau N,et al.Large magnetic entropy change abov e 300K in a colossal magnetoresistive material La0.7Sro.3Mn0.98Nio.02O3. J.Appl.Phys,2005,97:103901-1～5.
[32]Zener C.Interaction between the d-shells in the transition metals ferrom agnetic compounds of manganese with perovskite structure.Phys.Rev,19 50,82(3):403～405.
[33]Schlottmann P.Phase diagram and spin-canting effects in electron-doped LaMnO3.Phys.Rev.B,2008,77:104446-1-7.
[34]Eom T W,Hyun Y H,Park J S,Lee Y P,Prokhorov V G.,Flis V S,Svetc hnikoV L v.Griffiths phase and charge ordering in electron-doped La0.9 Ce0.1MnO3 films.Appl.Phys.Lett.2009,94:152502-1-3.
[35]Fuchs D,Schweiss P,Adelmann P,et al.Ferro-magnetic order in the electr on-doped system La,-xCexCoO3.Phys.Rev.B 2005,72:014466-1～4.
[36]Wang D J,Sun J R,Zhang S Y,Liu G J,Shen B G.Hall effect in Lao.7C eo.3MnO3+δ films with variable oxygen content.Phys.Rev.B,2006,73:1444 03-1-6.
[37]Boudayay C,Laroussiy L,Dhahriy E,et al.Magnetic and magnetoresistanc e properties in rhombohedral La1-xK+xMn03 perovskite-type compounds. J.Phys.Condens.Matter,1998,(10):7485-7492.
[38]Prokhorov V. G.,Kaminsky G. G.,Flis V S,Hyun Y H,Park S Y,and Lee Y PSvetchnikov V L.Magnetic ordering and charge transport in electr on-doped La,-yCeyMnO3 (0.1≤ y≤ 0.3)Films. Low Temp. Phys.2009, 35(6):468-475.
[39]Krishnamoorthy C,Sethupathi K,Sankaranarayanan V,Nirmala R,Malik S K.Magnetic and magnetotransport properties of Ce doped LaMnO3.Jou rnal of Alloys and Compounds,2007,438:1-7.
[40]Mina B I.,Kwona S K,Leeb B W,Kang J-S.Electronic structures of ele ctron-doped manganite:La0.7Ce0.3MnO3 Journal of Electron Spectroscop y and Related Phenomena 114-116(2001)801-805.
[41]Bajaj Kavita,Jesudasan John,Bagwe Vivas,CKothari D,Pratap Raychaudh uri. Correlation between effects of electric current and magnetic field on transport properties of electron-doped manganite La0.7Ce0.3MnO3 thi n films.J.Phys.Condens.Matter,2007,19:382202-1-8.
[42]Gayone J E,Abbate M,Alejandro G.,Lamas D G.,Tovar M,Zampieri G.. Ce valence in La0.47Ce0.20Ca0.33Mn03.Journal of Alloys and Compounds ,2004,369:252-255.
[43]Das S,Poddar A,Roy B,Giri S.Studies of transport and magnetic proper ties of Ce-doped LaMno3.Journal of Alloys and Compounds,2004,365:9 4-101.
[44]Philip J,Kutty T R N.Effect of valence fluctuations in A sites on the t ransport properties of La1-xRxMnO3 (R=Ce,Pr).J.Phys.:Condens. Matter,1 999,11:8537～8546.
[45]Chang W J,Tsai J Y,Jeng H T,et al.Electronic structure and transport p roperties of La0.7Ce0.3MnO3.Phys.Rev.B,2005,72:132410-1-4.
[46]Manjunath B,Bellakki C,Shivakumara N Y,Vasanthacharya A S.Prakash Rapid synthesis of room temperature ferromagnetic Ag-doped LaMnO3 perovskite phases by the solution combustion method Materials Resea rch Bulletin 45(2010)1685-1691.
[47]Laiho R K,Lisunov G.,Lahderanta E,et al.Influence of the phase separat ion effect on low-field magnetic properties of Lai1-xBaxMnO3.J.Magn.Ma gn.Mater.,2005,293:892-902.
[48]胡季帆,梅良模,丁志强.钙钛矿氧化物(Ca, Ba)0.35Mn1-xFexOy的磁电阻效应.稀土,2000,21(1)：19-22.
[49]Cai J W,Wang C,Shen B G.et al.Colossal magnetoresistance of spin-gla ss perovskite La0.67Ca0.33Mn0.9Fe0.1O3.Appl.Phys.Lett.1997,71 (12):1727-1 729.
[50]Bhame S D,Joseph Joly V. L, Joy P A.Effect of disorder on the magn etic properties of LaMn0.5Fe0.5O3.Phys.Rev.B,2005,72:054426-1-7.
[51]Karmakar S,Taran S,Chaudhuri B K,et al.Disorder-induced short-range f erromagnetism and cluster spin-glass state in sol-gel derived La0.7Ca0.3 Mn1-xCdxO3(0≤x≤0.2).Phys.Rev.B,2006,74:104407-1-10.
[52]Kirilyuk A,Demyk K,Helden G.,Meijer G..et al.Atomic clusters of magn etic oxides:Structure and phonons. J.Appl.Phys.,2003,93(10):7379-738 1.
[53]Manjunath B,Bellakki C,Shivakumara N Y,Vasanthacharya A S. Prakash. Rapid synthesis of room temperature ferromagnetic Ag-doped LaMnO 3 perovskite phases by the solution combustion method.Materials Resea rch Bulletin,2010,45:1685-1691.
[54]Bera A K,Yusuf S M.Ferromagnetic clusters in the Brownmillerite bila yered compounds Ca2.5-xLaxSr0.5GaMn2O8 An approach to achieve layer ed spintronics materials.Jourl of Appled Physics,2010,107:013911-1-4.
[55]Samal D,Shivakumara C,Anil Kumar P S.The incongruous observation of magnetic phase separation in La0.85Sr0.15CoO3 spin glass system. Jou r1 of Appled Physics,2009,106:123920-1-8.
[56]Tang Y K,Ma X,Kou Z Q,et al.Slight La doping induced ferromagneti c clusters in layered La3-3xSri+3xMn3O10(x=1.00,0.99,0.95).Phys.Rev.B,20 05,72:132403-1-4.
[57]Autret C,Martin C,Rotoux R,et al.Coexistance of ferromagnetism and a ntiferromagnetism in the La0.08Ca1.92-MnO4 series. J.Magn.Magn. Mater.2 004,284:172-180.
[58]Chatterjee S,Giri S,Majumdar S.Metastability around the insulator-metal transition in La0.2Pr0.5Ca0.3MnO3. Jourl of Appled Physics,2010,107:11 3909-1-5.
[59]Huang X H,Ding J F,Jiang Z L,Yin Y W,Yu Q X,Li X G.Dynamic pr operties of cluster glass in La0.25Ca0.75MnO3 nanoparticles.Jourl of Appl ed Physics,2009,106:083904-1-5.
[60]Geetha Kumary T,Lin J G.,Valsakumar M C.Magnetic phase separation in Ndo.5(Ca,Sr)0.5Mn03. Jourl of Appled Physics,2010,108:043922-1-4.
[61]Jonker G H,Van Santen J H.Ferromagnetic compounds of manganese with perovskite structure. Physica,1950,16:337-348.
[62]Urushibara A,Moritomo Y,Aima T,et al.Insulator-metal transition and gi ant magnetoresistance in Lai.xSrxMnO3.Phys.Rev.B,1995,51(20):14103-1 4109.
[63]Imamorid S,Tokunaga M,Hakuta S,et al.Room temperatuer low-field col ossal magnetoresistance in Lao 7Sro.3MnO3.Appl.Phys.Lett.,2006,89:17250 8-1-3.
[64]Parmar R N,Markna J H,Kuberkar D G..Swift-heave-ion-irradiation-indu ced enhancement in electrical conductivity of chemical solution deposit ed Lao.7Bao.3Mn03 thin films. Appl.Phys.Lett.,2006,89:202506-1-3.
[65]Ang R,Lu W J,Zhang R L,et al.Effects of Co doping bilayered manga nite LaSr2Mn2O7:Resistivity,themoelectric power and thermal conductivit y. Phys. Rev.B,2005,72:184417-1-8.
[66]Neupane K P,Cohn J L,Terashita H.,et al.Doping dependence of polaro n hopping energies in La1-xCaxMnO3(0
[68]Owens F J.Giant magneto radio frequency absorption in magnetoresisti ve ma-terials Lao.7(Sr,Ca)0.3MnO3.J. Appl. Phys.1997,82(6):3054-3057.
[69]Patil S Ⅰ,Lofland S E,Shu Q Q,et al.Half-pointfields for microwave ma g-netoabsorption in colossal magneto-resistance manganite powders. J. Appl. Phys.,2000,87(5):2652-2654.
[70]Rivas-Murias B R,Ramos C A,Senaris-Rodriguez M A,et al.Non-resona nt microwave absorption in Pr1-xBaxCoO3-δ. J. Magn.Magn.Mater.2004, 272-276:e1635-e1636.
[71]Huhtinen H,Laiho R,Vlasenko L S,et al.Effect of illumination on mag-netization and microwave absorption of La1-xCaxMn03 (x<0.2) films. J.Magn.Magn.Mater.2008,320(11):1747-1752.
[72]Li G,Hu G. QZhou H D,et al.Attractive microwave-absorbing propertie s of La1-xSrxMnO3.Mater.Chem.Phys.,2002,75(1):101-104.
[73]胡国光,尹萍,吕庆荣.La1-xSrxMnO3微波吸收特性的研究.磁性材料及器件,2000,3 1(6)：14～17.
[74]胡国光,尹萍,吕庆荣.La1-xSrxMnO3氧化物的导电和吸收特性.中国稀土学报,2002,20(2)：179～180.
[75]孙杰,刘建华,李松梅.La0.5Sr0.5MnO3纳米晶体的制备与电磁性能研究.稀有金属材料与工程,2005,34(11)：1814～1817.
[76]Yang R B,Tsay C Y,Liang W F,Lin C K.Microwave absorbing properti es of La0.7Sr0.3Mn03 composites with negative magnetic susceptibility [J]. J. Appl. Phys.2010,107:09A523-1-3.
[77]Tsay C Y,Yang R B,Hung D S,Hung Y H,Yaoand Y D,Lin C K.Invest igation on electromagnetic and microwave absorbing properties of La0.7 Sr0.3MnO3 carbon nanotube composites [J]J. Appl. Phys.2010,107:09A5 02-1-3.
[78]Yulan Cheng,Jianming Dai,Xuebin Zhu,Dajun Wu,Yuping Sun.Preparatio n magnetic and microwave absorption properties of La0.5Sro.sMnO3/La (OH)3 composites.Materials Research Bulletin,2010,45:663-667
[79]Zhou K-S,Xia H,Huang K-L,et al.The microwave absorption properties of Lao.8Sr0.2Mn1-yFey03 nano-crystalline powders in frequency range o f 2-18GHz.Phyica B,2009,404:175-179.
[80]ZHOU Ke-sheng, DENG Jian-jie, YIN Li-song,et al.The microwave ab sorption properties of La0.8Bao.2MnO3, Trans.Nonferrous Met. Soc. Chin a,2007,17(5):947-950.
[81]周克省,刘宝刚,黄可龙,尹荔松. Lao.6Ceo.4Mn1-yFeyO3微波吸收特性.中国稀 土学报,2009,27(1)：81-85
[82]张立德.纳米材料与纳米结构[M].北京：科学出版社,2001,51-66,322-338.
[83]Tao T,Cao Q Q,Cu K M,Xu H Y,Zhang S Y,and Du Y W.Giant magn etoresistance of the La1-xAgxMn03 polycrystalline inhomogeneous granu lar system. Appl.Phys Lett.2000,77:723-725.
[84]王广涛,张敏平,尚学府.La1-xAgxtMnO3和La1-xNaxMnO3的对比研究.低温物理学报.2005,27(1)：67～73.