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arXiv 0901.0807cond-mat.mtrl-sci
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单相Mn掺杂ZnO的合成与表征

Synthesis and characterization of single phase Mn doped ZnO

Soubhik Chattopadhyay, S. Dutta, Aritra Banerjee, D. Jana, S. Bandyopadhyay, Sanjay Chattopadhyay, A. Sarkar

摘要:

采用传统固相烧结法制备了Zn_(1-x)Mn_xO系列样品。确定了掺杂到什么程度才能合成出单相多晶Mn掺杂ZnO样品,这是制备稀磁半导体的前提条件之一,并分析了它的某些其它物理性质。在合成样品中,Mn的比例从1原子%变化到5原子%。然而,仅对于2原子% Mn掺杂的样品改变研磨时间(6、12、24、48和96小时),而对于其它样品(1、3、4和5原子% Mn掺杂),研磨时间保持固定在96小时。室温X射线衍射(XRD)结果表明,Mn掺杂量为3at%时,所有样品均为纤锌矿结构,未发现Mn和/或其氧化物的偏聚; Mn掺杂量为4at%时,样品中除了常见的ZnO峰外,还出现了一个较弱的ZnMn 2 O 4峰,且该杂质峰的强度在Mn掺杂量为5at%时进一步增强。因此,超过3at%掺杂的单相行为被破坏。所有2at%Mn掺杂样品的带隙估计为3.21至3.19 eV,并且通过晶界捕获模型解释了这种低带隙值的原因。室温电阻率测量显示电阻率增加到研磨48小时,并且随着进一步研磨,其饱和。用正电子湮没寿命谱(PAL)技术研究了这些样品的缺陷态。这里,正电子的所有相关寿命参数,即自由湮灭(τ 1)、在缺陷位点处的自由湮灭(τ 2)和平均寿命(τ av)随着研磨时间而增加。

英文摘要:

Different samples of Zn1-xMnxO series have been prepared by conventional solid state sintering method. It has been identified, up to what extent of doping enable us to synthesize single-phase polycrystalline Mn doped ZnO samples which is one of the prerequisite for dilute magnetic semiconductor and we have analyzed its certain other physical aspects. In synthesizing the samples proportion of Mn varies from 1 at% to 5 at%. However the milling times have been varied (6, 12, 24, 48 & 96 hours) for only 2 at% Mn doped samples while for other samples (1, 3, 4 & 5 at% Mn doped) the milling time has been kept fixed at 96 hours. Room temperature X-Ray diffraction (XRD) data reveal that all of the prepared samples up to 3 at% of Mn doping exhibit wurtzite-type structure, no segregation of Mn and/or its oxides has been found. The 4 at% Mn doped samples show a weak peak of ZnMn2O4 apart from usual other peaks of ZnO and the intensity of this impurity peak has been further increased for 5 at% of Mn doping. So beyond 3 at% doping single-phase behavior is destroyed. Band gap for all the 2 at% Mn doped samples have been estimated as between 3.21 to 3.19 eV and reason for this low band gap values has been explained through the grain boundary trapping model. The room temperature resistivity measurement shows increase of resistivity up to 48 hours of milling and with further milling it saturates. The defect state of these samples has been investigated by using positron annihilation lifetime (PAL) spectroscopy technique. Here all the relevant lifetime parameters of positron i.e. free annihilation (tau 1), at defect site (tau 2) and average (tau av) increases with milling time.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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