聚吡咯-钴锌铁氧体复合材料的制备及性能

用聚丙烯酰胺凝胶法制备纳米Co0.5Zn0.5Fe2O4铁氧体,再用原位聚合法制备聚吡咯-钴锌铁氧体(PPy-Co0.5Zn0.5Fe2O4)复合材料。使用X射线衍射仪(XRD)和扫描电子显微镜(SEM)表征了复合材料的结构和形貌,用振动样品磁强计(VSM)和矢量网络分析仪测试了复合材料的磁性能和介电性能。结果表明:样品为纯PPy和PPy-Co0.5Zn0.5Fe2O4,平均粒径分别约为200 nm和180 nm;Co0.5Zn0.5Fe2O4的磁化强度(Ms)和剩余磁化强度(Mr)分别为65.95 emu/g和15.44 emu/g,均大于PPyCo0.5Zn0.5Fe2O4,但矫顽力(Hc)为153.51 Oe,小于PPy-Co0.5Zn0.5Fe2O4;PPy的介电损耗(tanε=ε'/ε')大于PPy-Co0.5Zn0.5Fe2O4,反射损耗小于PPy-Co0.5Zn0.5Fe2O4,这是Co0.5Zn0.5Fe2O4的引入所致;在频率为15.2 GHz处,PPy-Co0.5Zn0.5Fe2O4复合材料的反射损耗达到最大值-16.4 dB,频带宽为2.5 GHz。     

Ni_(0.5)Zn_(0.5)Fe_2O_4铁氧体的制备及其电磁损耗性能

以Zn(NO3)2.6H2O、Ni(NO3)2.6H2O和Fe(NO3)3.9H2O及柠檬酸为原料,采用溶胶-凝胶法制备前驱体,在1 200℃下煅烧3 h合成ZnFe2O4和Ni0.5Zn0.5Fe2O4铁氧体粉体。利用差热分析、X射线衍射、扫描电镜、透射电镜和红外光谱等测试手段对产物进行分析和表征。结果表明:ZnFe2O4和Ni0.5Zn0.5Fe2O4属于立方晶系尖晶石结构,结晶完整,晶粒大小在100 nm左右。在0.2~1.8 GHz的频率下对产品进行了电磁损耗性能测试,发现Ni0.5Zn0.5Fe2O4具有较好的电磁损耗特性。     

La掺杂纳米晶Ni-Zn铁氧体的制备及电磁性能

采用高分子凝胶法制备了Ni0.5Zn0.5LaxFe2-xO4（x=0,0.02,0.05和0.08）纳米晶铁氧体.采用X射线衍射仪（XRD）、透射电镜（TEM）和HP8510网络分析仪分别对其结构、形貌和电磁性能进行了研究.结果表明,当x=0,0.02和0.05时,所得粉体为纯立方晶系尖晶石结构.Ni0.5Zn0.5Fe2O4粉体平均粒径为70nm.随着La离子掺杂量的增加,红外光谱中550cm-1处吸收峰向高波数移动,420cm-1处吸收峰向低波数移动.La离子的掺杂对Ni-Zn铁氧体的电磁性能有一定的影响.在X波段,与Ni0.5Zn0.5Fe2O4铁氧体相比,掺杂La的Ni-Zn铁氧体的tanδm值降低,tanδε值升高.Ni0.5Zn0.5La0.02Fe1.98O4铁氧体的tanδε平均值为0.616.     

Ni0.5Zn0.5Fe2O4粉末化学镀铜前后的电磁性能

本文用溶胶-凝胶自燃烧法制备了Ni0.5Zn0.5Fe2O4粉末颗粒,以甲醛为还原剂在Ni0.5Zn05Fe2O4颗粒表面进行了化学镀铜,制备了Cu/Ni0.5Zn0.5Fe2O4复合粉体.用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对镀铜前的Ni0.5Zn0.5Fe2O4颗粒以及镀铜后的复合纳米颗粒进行了表征.对镀铜前的Ni0.5Zn0.5Fe2O4粉体和不同镀铜量的Cu/Ni0.5Zn0.5Fe2O4复合粉体进行了电磁性能的研究,结果表明镀铜后镍锌铁氧体的吸波性能明显提高,增重量为65%的Cu/Ni0.5Zn0.5Fe2O4复合粉体在频率为11GHz处反射率可达-12dB左右.     

溶胶自燃烧法制备纳米Mn0.5Zn0.5Fe2O4和BaZn2Fe16O27粉体

以柠檬酸与硝酸盐为原料通过溶胶自燃烧法制备出纳米Mn0.5Zn0.5Fe2O4和BaZn2Fe16O27粉体.采用XRD、TG-DSC、TEM、AA、BET及VSM等方法对产物进行了表征,结果表明,在1000℃灼烧后分别得到了单相尖晶石型Mn0.5Zn0.5Fe2O4纳米粒子和六角磁铅石型BaZn2Fe16O27纳米粒子,其晶型完整,分散性好.     

X、U铁氧体的溶胶-凝胶合成及微波性能研究

以檬檬酸铁、碳酸钡、硝酸钴、硝酸锌以及柠檬酸等为原料，采用sol-gel工艺合成了Ba2Zn2Fe28O46(Zn2-X)、Ba2Co2Fe28O46(Co2-X）、Ba4Zn2Fe36O60(Zn2-U)、Ba4Co2Fe36O60(Co2-U)铁氧体。采用XRD、SEM对其相成分和显微结构进行研究。并对其复介电常数、复磁导率在100MHz-6.0GHz下的变化规律进行了对比。结果表明，铁氧体试样的磁导率虚部随测试频率的变化曲线上显示出非常明显的由自然共振引起的共振峰。     

Ce取代对纳米晶Ni0．5Zn0．5Fe2O4电磁性能的影响

以丙烯酰胺为聚合单体,N,N-亚甲基双丙烯酰胺为网络剂,采用聚丙烯酰胺凝胶法制备了尖晶石型Ni0.5Zn0.5CexFe2-xO4(x=0, 0.05)纳米晶.采用X射线,FT-IR,TEM和波导等方法对产物进行了表征.X射线结果表明,当煅烧温度为600℃时,形成纯相的尖晶石型Ni0.5Zn0.5CexFe2-xO4(x=0,0.05);由透射电镜照片可知Ni0.5Zn0.5Fe2O4平均粒径约为30nm;纳米晶体在8.2～12.4GHz的测试频率范围内具有介电损耗(ε")和磁损耗(μ"),Ni0.5Zn0.5Ceo.05Fe1.95O4的ε" 和μ"均高于Ni0.5Zn0.5Fe2O4,Ni0.5Zn0.5Ce0.05Fe1.95O4的ε"和μ"的最大值分别为0.93和0.15.     

纳米Ni0.5Zn0.5Fe2O4铁氧体的制备及电磁损耗特性研究

采用NH4 HCO3与FeCl3·6H2O、Zn(NO3)2·6H2O、Ni(NO3)2·6H2O进行室温固相反应制得Fe(OH)3、Zn3(OH)4CO3·H2O、Ni3(OH)4CO3·4H2O混合前驱物,先经微波加热,再热分解制得纳米粉体.利用激光粒度分析仪、XRD、SEM和TEM对分解产物进行了表征,获得了形貌为球形、颗粒分布均匀、平均粒度为62nm、尖晶石结构的纳米Ni0.5Zn0.5Fe2O4复合铁氧体粉体.经测试样品的相对介电常数和相对磁导率后,发现该纳米铁氧体粉体在100～1800MHz内具有良好的电损耗和磁损耗性能.     

Ni0.5Zn0.5Nd0.02Fe1.98O4-聚苯胺纳米复合材料的制备及电磁性能（英文）

在Ni0.5Zn0.5Nd0.02Fe1.98O4纳米粒子表面原位聚合苯胺制备了Ni0.5Zn0.5Nd0.02Fe1.98O4-聚苯胺(PANI)纳米复合材料.铁氧体含量为0%、15%和30%样品的结构、形貌和电磁性能分别采用X射线衍射仪(XRD)、透射电子显微镜(TEM)和HB8510B网络分析仪进行了研究.结果表明,聚苯胺包覆层对Ni0.5Zn0.5Nd0.02Fe1.98O4的结晶度有一定影响.在X波段(8.2～12.4 GHz),复介电常数的实部随铁氧体含量的增加而减小,虚部随铁氧体含量的增加而增大.复磁导率的实部和虚部都随铁氧体含量的增加而增大.     

尖晶石型铁氧体Co1-xZnxFe2O4的制备及其光催化性能研究

采用溶胶-凝胶法制备了尖晶石型铁氧体Co1-xZnx Fe2O4.利用XRD、SEM表征了纳米颗粒的结构和形貌,结果表明所合成的样品为尖晶石型铁氧体,形貌呈圆球状,粒径均匀,直径约为50nm.通过考察样品对甲基橙的降解情况研究了其光催化活性,结果表明经过A位Zn离子掺杂的Co1-xZnxFe2O4样品光催化活性明显提高.     

One-dimensional SrFe12O19/Ni(0.5)Zn(0.5)Fe2O4 composite ferrite nanofibers and enhancement magnetic property

SrFe12O19/Ni(0.5)Zn(0.5)Fe2O4 composite ferrite nanofibers of diameters about 100 nm with mass ratio 1:1 have been prepared by the electrospinning and calcination process. The SrFe12O19/Ni(0.5)Zn(0.5)Fe2O4 composite ferrites are formed after calcined at 700 degrees C for 2 hours. The composite ferrite nanofibers are fabricated from nanosized Ni(0.5)Zn(0.5)Fe2O4 and SrFe12O19 ferrite grains with a uniform phase distribution. The ferrite grain size increases from about 11 to 36 nm for Ni(0.5)Zn(0.5)Fe12O4 and 24 to 56 nm for SrFe12O19 with the calcination temperature increasing from 700 to 1100 degrees C. With the ferrite grain size increasing, the coercivity (Hc) and remanence (Mr) for the SrFe12O19/Ni(0.5)Zn(0.5)Fe2O4 composite ferrite nanofibers initially increase, reaching a maximum value of 118.4 kA/m and 31.5 Am2/kg at the grain size about 40 nm (SrFe12O19) and 24 nm (Ni(0.5)Zn(0.5)Fe2O4) respectively, and then show a reduction tendency with a further increase of the ferrite grain size. The specific saturation magnetization (Msh) of 63.2 Am2/kg for the SrFe12O19/Ni(0.5)Zn(0.5)Fe2O4 composite ferrite nanofibers obtained at 900 degrees C for 2 hours locates between that for the single SrFe12O19 ferrite (48.5 Am2/kg) and the single Ni(0.5)Zn(0.5)Fe2O4 ferrite (69.3 Am2/kg). In particular, the Mr value 31.5 Am2/kg for the SrFe12O19/Ni(0.5)Zn(0.5)Fe2O4 composite ferrite nanofibers is much higher than that for the individual SrFe12O19 (25.9 Am2/kg) and Ni(0.5)Zn(0.5)Fe2O4 ferrite (11.2 Am2/kg). These enhanced magnetic properties for the composite ferrite nanofibers can be attributed to the exchange-coupling interaction in the composite.     

参杂尖晶石型镍基铁氧体的磁性能与介电性能

采用溶胶-凝胶法制备了立方晶系尖晶石型镍基铁氧体微粉Ni0.5M0.5Fe2O4（M=Zn、Mn、Cu）,采用X射线衍射仪、扫描电子显微镜、振动样品磁强计和矢量网络分析仪对粉末的结构、形貌、磁性以及电磁性能进行了表征,结果表明,三种粉末在室温下具有超顺磁性,其饱和磁化强度MS分别为76．0、59．4和54．4emu·g-1。在2—11GHz范围内,Ni0.5M0.5Fe2O4的电磁损耗角正切值tgδ随频率的增大而逐渐减小;Ni0.5M0.5Fe2O4和 Ni0.5M0.5Fe2O4的tgδ随频率的增大先增大后减小。     

Preparation of a new nanosized As2O3/Mn0.5Zn0.5Fe2O4 thermosensitive magnetoliposome and its antitumor effect on MDA_MB_231 cells

The purpose of our research is to explore the preparation method of a new nanosized As2O3/Mn0.5Zn0.5Fe2O4 thermosensitive magnetoliposome and study its antitumor effect on MDA_MB_231 cells. The liposomes prepared by the method of rotatory film and high-pressure homogenization were detected by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), nano-particles detector, atom fluorescence spectrophotometer and differential scanning calorimetry (DSC). The therapeutic effects of the nanosized thermosensitive magnetoliposomes combined hyperthermia on human MDA_MB_231 cells in vitro were evaluated by MTT assay and flow cytometry assay. The results indicated that the nanosized As2O3/Mn0.5Zn0.5Fe2O4 thermosensitive magnetoliposomes were prepared successfully. The liposomes were spherical, and most of them were single-room. The exat average diameter of them was 103.8 nm. EDS showed each nanosized As2O3/Mn0.5Zn0.5Fe2O4 thermosensitive magnetoliposome contained P, Mn, Zn, Fe, and As elements, and this proved liposomes have successfully entrapped As2O3 and Mn0.5Zn0.5Fe2O4. The encapsulation ratio of As2O3 detected by atom fluorescence spectrophotometer was 82.16%. The result of heating test showed that Mn0.5Zn0.5Fe2O4 can serve as a heating source upon alternating magnetic field (AMF) exposure leading the nanosized thermosensitive liposomes to reach its phase transition temperature (42.52 degrees C) and release As2O3. MTT assay and flow cytometry assay revealed that the therapeutic effect of the nanosized As2O3/Mn0.5Zn0.5Fe2O4 thermosensitive magnetoliposomes combined with hyperthermia upon AMF on MDA_MB_231 cells was much better than other groups.     

静电纺丝法制备的Co0.6Ni0.3Cu0.1Fe2O4和Co0.6Ni0.3Zn0.1Fe2O4纳米纤维的结构及磁性能

采用静电纺丝技术制备出表面光滑、直径均匀的Co_(0.6)Ni_(0.3)Cu_(0.1)Fe_2O_4/PVP和Co_(0.6)Ni_(0.3)Zn_(0.1)Fe_2O_4/PVP纳米纤维前驱丝,经500~900℃煅烧后得到Co_(0.6)Ni_(0.3)Cu_(0.1)Fe_2O_4和Co_(0.6)Ni_(0.3)Zn_(0.1)Fe_2O_4纳米纤维。用TG-DSC、XRD、SEM及VSM现代测试分析手段对Co_(0.6)Ni_(0.3)Cu_(0.1)Fe_2O_4和Co_(0.6)Ni_(0.3)Zn_(0.1)Fe_2O_4纳米纤维的结构、形貌及磁学性能进行测试表征。结果表明:在空气气氛中经500~900℃煅烧后可得到纯尖晶石相、结晶度良好的纳米纤维或短纤维;当温度为700℃时,Co_(0.6)Ni_(0.3)Cu_(0.1)Fe_2O_4和Co_(0.6)Ni_(0.3)Zn_(0.1)Fe_2O_4纳米纤维的形貌细长而光滑且直径相对均匀,大约为80nm;此时Co_(0.6)Ni_(0.3)Cu_(0.1)Fe_2O_4纳米纤维则保有较高的剩磁比(M_r/M_s)及矫顽力,分别为0.56和1 088.87Oe。在500℃、600℃、700℃、800℃、900℃煅烧后,Co_(0.6)Ni_(0.3)Zn_(0.1)Fe_2O_4纳米纤维的饱和磁化强度分别比Co_(0.6)Ni_(0.3)Cu_(0.1)Fe_2O_4纳米纤维增大了14.5%、7%、16%、10.7%、8%,而矫顽力则分别降低了38%、51%、50%、46%、46.7%。两种纳米纤维的饱和磁化强度及矫顽力存在差异,为CoNi铁氧体在电磁方面的应用提供了很好的参考。     

移相器材料Zn、Ti、Sn替代锂铁氧体

为了研制高性能自动跟踪同步通信卫星相控天线阵中的移相器材料,采用普通陶瓷工艺,并加入微量杂质：Bi₂O₃、NiO、Co₂O₃和MnCO₃,且利用氧气氛烧结制备了目前尚未见报道的铁氧体Li_0．625Zn_0．1Ti_0．25Sn_0．1Fe_1．925O₄．结果表明,该材料具有较高的居里温度和较低的介电损耗.并对锂铁氧体Li_0.5（1-y）Zn_yFe_{2.5（1-0.2y）}O₄的微波特性进行了讨论.     

Effect of Substitutions of Zn for Mn on Size and Magnetic Properties of Mn–Zn Ferrite Nanoparticles

In this study Mn?CZn ferrite nanoparticles (Mn_(1?x)Zn _x Fe₂O₄, x=0, 0.3 and 0.5) were produced by a chemical co-precipitation method. The structure and size of the Mn?CZn ferrite nanoparticles were characterized using X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Results show that the ferrite nanoparticles have the spinel structure. It was found that the size of Mn?CZn ferrite nanoparticles decreases by increasing of the Zn concentration. The magnetic properties of Mn?CZn ferrite nanoparticles were investigated with a vibrational sample magnetometer (VSM) and it was observed that Mn_0.7Zn_0.3Fe₂O₃ ferrite nanoparticles have the maximum saturation magnetization and that the initial susceptibility decreases with the increase in Zn concentration.     

Synthesis, Characterization and Electromagnetic Studies on Nanocrystalline Nickel Zinc Ferrite by Polyacrylamide Gel

Nanocrystalline nickel zinc ferrite powders （Ni=Zn1-xFe2O4, A for x=0, B for x=0.2, C for x=0.5, D for x= 0.8 and E for x= 1） were synthesized by polyacrylamide gel method. X-ray diffraction （XRD）, transmission electron microscopy （TEM） and wave-guide were used to characterize the composition. The XRD results show that the dried gel powders are amorphous, and the characteristic peaks of the spinel Ni0.5Zn0.5Fe2O4 appear after the gel is calcined at 400℃ for 1 h. When the calcining temperatures are 600 and 800℃, the average grain sizes are identified by TEM to be 10 and 30 nm, respectively. The NixZn1-xFe2O4 powders have both dielectric loss and magnetic loss in the frequency range of 8.2-11.0GHz. With the increase of Ni^2＋ ions content, the dielectric parameters （ε′） and permeability （u′） of the NixZn1-xFe2O4 powders decrease while the dielectric loss （ε″）, magnetic loss （u″） and the reflection loss increase.