Multi-layered nanostructure Bi2Se3 grown by chemical vapor deposition in selenium-rich atmosphere
Multi-layered nanostructure Bi2Se3 grown by chemical vapor deposition in selenium-rich atmosphere
复制标题
富硒气氛中化学气相沉积法生长多层纳米结构 Bi2Se3
DOI：
10.1016/j.apsusc.2014.08.103
复制
发表时间：
2014
影响因子：
6.7
通讯作者：
Xue You Xu
中科院分区：
文献类型：
--
作者：
Mei Liu;Fu Yan Liu;Bao Yuan Man;Dong Bi;Xue You Xu
采用水热合成法成功地合成了赤铁矿(α-Fe_2O_3)纳米粒子。X-射线粉末衍射仪分析表明，样品中形成了纳米晶α-Fe2O_3相。透射电子显微镜(TEM)测量表明，所制备的赤铁矿纳米颗粒呈球形，粒度分布较窄。经透射电子显微镜和X射线衍射仪测定，赤铁矿纳米粒子的平均粒径约为8 nm。利用超导量子干涉装置(SQUID)测量了样品的磁学性质。对赤铁矿纳米颗粒磁性能的研究表明，在Tirr=1103kK(不可逆温度)下，场冷却(FC)和零场冷(ZFC)磁化曲线之间存在发散。ZFC磁化曲线显示最大磁化温度atTb=152K(阻断温度)。样本没有表现出Morin转变。它们(H)(磁化强度与磁场的关系)在300℃时显示出超顺磁性氧化铁纳米颗粒(SPION)的性质。用朗之万函数成功地对它们(H)的数据进行了拟合，测得了磁矩μp=2657，μ带直径d=8.1 nm。此外，磁性测量表明，在室温下有很高的磁化强度(MS=33.98×emu/g)，这是一种在自旋电子学和生物医学中应用的理想材料。利用纳米粒子的核壳结构描述了赤铁矿纳米粒子的高磁化程度。
Hematite (α-Fe2O3) nanoparticles are successfully synthesized by using the hydrothermal synthesis method. An X-ray powder diffraction (XRPD) of the sample shows formation of the nanocrystalline α-Fe2O3phase. A transmission electron microscopy (TEM) measurements show spherical morphology of the hematite nanoparticles and narrow size distribution. An average hematite nanoparticle size is estimated to be about 8 nm by TEM and XRD. Magnetic properties were measured using a superconducting quantum interference device (SQUID) magnetometry. Investigation of the magnetic properties of hematite nanoparticles showed a divergence between field-cooled (FC) and zero-field-cooled (ZFC) magnetization curves belowTirr= 103 K (irreversibility temperature). The ZFC magnetization curve showed maximum atTB= 52 K (blocking temperature). The sample did not exhibit the Morin transition. TheM(H) (magnetization versus magnetic field) dependence at 300 K showed properties of superparamagnetic iron oxide nanoparticles (SPION). TheM(H) data were successfully fitted by the Langevin function and magnetic momentμp= 657 μBand diameterd= 8.1 nm were determined. Furthermore, magnetic measurements showed high magnetization at room temperature (MS= 3.98 emu/g), which is desirable for application in spintronics and biomedicine. Core–shell structure of the nanoparticles was used to describe high magnetization of the hematite nanoparticles.