Mn掺杂ZnO稀磁半导体材料的制备和磁性研究

采用共沉淀方法制备了名义组分为Zn_1-xMn_xO(x=0.001,0.005,0.007,0.01)的Mn掺杂的ZnO基稀磁半导体材料,并研究了在大气气氛下经过不同温度退火后样品的结构和磁性的变化.结果表明：样品在600℃的大气条件下退火后, 仍为单一的六方纤锌矿结构的ZnO颗粒材料;当样品经过800℃退火后,Mn掺杂量为0.007,0.01的样品中除了ZnO纤锌矿结构外还观察到ZnMnO₃第二相的存在.磁性测量表明,大气条件下600℃退火后的样品,呈现出室温铁磁性;而800℃退火后的样品,其室温铁磁性显著减弱,并表现为明显的顺磁性.结合对样品的光致发光谱的分析,认为合成样品的室温铁磁性是由于Mn离子对ZnO中的Zn离子的替代形成的. 关键词： ZnO 掺杂 稀磁半导体 铁磁性     

氧化石墨烯增强环氧树脂复合材料的制备及其力学性能研究

以天然石墨为原料，利用改进的Hummers法制备氧化石墨烯，并对其进行X-射线衍射（XRD）和傅里叶变换红外光谱（FT-IR）表征。之后利用一种新型的有机溶剂三缩水甘油基对氨基苯酚（TGPAP）作为相转移剂和表面活性剂，将氧化石墨烯（GO）从水溶液转移到环氧树脂基体中，去除水分，加入固化剂进而得到混合液，最后利用浇铸法得到复合材料。通过万能测试拉力机对复合材料的拉伸性能和弯曲性能进行测试，结果表明氧化石墨烯的加入能够有效增强复合材料的力学性能：在添加0.1%（质量分数）的氧化石墨烯时，复合材料拉伸强度达到最大值77.29 MPa，与不添加氧化石墨烯相比提高了26.60%；在添加1.0%的氧化石墨烯时，拉伸模量达到最大值2 451.99 MPa，与纯环氧树脂相比提高了21.69%。     

La-doped BiFe03： Synthesis and multiferroic property study

A new sol-foam-gel method was developed to fabricate La-doped BiFeO3 muttiferroic materials. It was demonstrated that a gradual increase in the content of La-doped into BiFeO3 results in its structure changing from rhombohedral to orthorhombic. A study of other property changes indicates that La-doping in BiFeO3 enhances its ferromagnetism and ferroelectricity. A temperature-dependent magnetization study suggests that the magnetic property of La-doped BiFeO3 samples varied from antiferromagnetic to ferromagnetic as the content of La-doped into BiFeO3 increased from 0 to 20%. Unique temperature-dependent zero field cooling （ZFC） and field cooling （FC） magnetization behaviors were observed in 15% La-doped BiFeO3 -- its ZFC temperature-dependent magnetization being ferromagnetic and its FC temperature- dependent magnetization being antiferromagnetic. A possible mechanism of such an interesting M-T behavior is discussed.     

玻璃及玻璃/钨复合材料药型罩的静破甲特性研究

为研究玻璃及玻璃/钨复合材料药型罩射流与靶板间的反应及其对破甲性能的影响,对两种材料射流侵彻后的45钢靶分别进行组织和性能测试分析.结果表明:玻璃药型罩适合在较大炸高条件下使用,而玻璃/钨药型罩适合在小炸高条件下使用.侵彻过程中玻璃射流与钢靶之间不发生反应,而玻璃/钨与钢靶之间发生反应生成了Fe-W相,使得射流能量部分横向耗散.玻璃及玻璃/钨射流在侵彻钢靶的过程中均会引起弹孔表面发生马氏体相变,且随着侵彻的深入,相变区域宽度呈增加的趋势.      

La-doped BiFeO_3:Synthesis and multiferroic property study

A new sol-foam-gel method was developed to fabricate La-doped BiFeO3multiferroic materials. It was demonstrated that a gradual increase in the content of La-doped into BiFeO3results in its structure changing from rhombohedral to orthorhombic. A study of other property changes indicates that La-doping in BiFeO3enhances its ferromagnetism and ferroelectricity. A temperature-dependent magnetization study suggests that the magnetic property of La-doped BiFeO3samples varied from antiferromagnetic to ferromagnetic as the content of La-doped into BiFeO3increased from 0 to 20%.Unique temperature-dependent zero field cooling(ZFC) and field cooling(FC) magnetization behaviors were observed in 15% La-doped BiFeO3— its ZFC temperature-dependent magnetization being ferromagnetic and its FC temperaturedependent magnetization being antiferromagnetic. A possible mechanism of such an interesting M–T behavior is discussed.     

Mg doping reduced full width at half maximum of the near-band-edge emission in Mg doped ZnO films

Sol--gol method was employed to synthesize Mg doped ZnO films on Si substrates. The annealing temperature-dependent structure and optical property of the produced samples were studied. An interesting result observed is that increasing Mg concentration in the studied samples induces the full width at half maximum (FWHM) of their near-band-edge (NBE) emission decrease and the defect related emission of the corresponding sample suppresses drastically. The possible mechanism of the observed result is discussed.     

Bi_（1-x）La_xFeO_3块体材料多铁性研究

采用溶胶-凝胶法并结合固相烧结工制备出了单相Bi1-xLaxFeO3（x=0,0.05,0.1,0.15,0.2）样品并对其结构、磁性和铁电性等物性进行了系统的分析研究,结果表明本文采用的方法所制备的样品具有单相性.少量La掺杂可有效地制材料中O空位,显著地提升材料的铁电性,同时La掺杂可有效地增强样品中的宏观铁磁性.     

A fabrication and magnetic properties study on Al doped Zn0.99Co0.01O dilution ferromagnetic semiconductors

This paper reports that a chemical method is employed to synthesize Co and Al co-doped ZnO,namely,Zn0.99 x Co0.01 Al x O dilution semiconductors with the nominal composition of x = 0,0.005 and 0.02.Structural,magnetic and optical properties of the produced samples are studied.The results indicate that samples sintered in air under the temperatures of 500 C show a single wurtzite ZnO structure and the ferromagnetism decreases with the increase of Al.Photoluminescence spectra of different Al-doped samples indicate that increasing Al concentration in Zn0.99 x Co0.01 Al x O results in a decrease of Zn i,which resembles the trend of the ferromagnetic property of the corresponding samples.Therefore,it is deduced that the ferromagnetism observed in the studied samples originates from the interstitial defect of zinc(Zni) in the lattice of Co-doped ZnO.     

Co掺杂的ZnO室温铁磁半导体材料制备与磁性和光学特性研究

采用溶胶-凝胶法制备出具有室温铁磁性的Co掺杂的ZnO稀磁半导体材料. 通过对样品的结构、磁性和发光特性的研究发现,样品具有室温铁磁性,并发现其铁磁性源于磁性离子对ZnO中Zn离子的取代. 对不同温度制备的样品的磁性以及其发光特性的变化研究发现,样品的铁磁性与样品中锌间隙位（Zn_i）缺陷的密度有关. 关键词： ZnO 稀磁半导体 铁磁性     

对加强高校美育管理工作的思考

美育在高校校园文化建设中,乃至在整个高校教育中的特殊地位及独特的作用,越来越充分显示出来。没有美育的教育是片面教育,同样,缺乏科学管理的高校美育也是不完善的美育。因而,加强高校美育的管理工作,对搞好整个高校的管理和全面提高人才素质,增强其育人功能,有极重要的现实意义。