Silva Alessandra S, Lourenço Sidney A, Dantas Noelio O
Universidade Federal de Uberlândia, Instituto de Física, Laboratório de Novos Materiais Isolantes e Semicondutores (LNMIS), Uberlândia, CEP 38400-902, Brazil.
Universidade Tecnológica Federal do Paraná, Engenharia de Materiais, CEP 86036-370, Londrina, Paraná, Brazil.
Phys Chem Chem Phys. 2016 Feb 17;18(8):6069-76. doi: 10.1039/c5cp06802a.
We studied the effect of Mn concentration on the optical, morphological and magnetic properties of Zn1-xMnxTe NCs grown in a glass matrix produced by the fusion method. The physical properties of these materials were determined by optical absorption (OA), transmission electron microscopy (TEM), atomic/magnetic force microscopy (AFM/MFM) and photoluminescence (PL). An analysis of the OA spectra, based on the crystal field theory (CFT), showed strong evidence that Mn(2+) ions were substitutionally incorporated into the Zn1-xMnxTe NCs until reaching the solubility limit (concentration, x = 0.100). Above this nominal concentration, TEM showed the onset of Mn-related phases, such as MnO and α-MnO2, in the PZABP glass system. AFM images showed that NC density on the surface of the glass matrix decreased as x-content increased. It is probable that MnO and MnO2 NCs would outnumber Zn1-xMnxTe NCs at higher concentrations - a conclusion that was corroborated by the OA spectra and TEM images. MFM images revealed that samples with Mn(2+) ions responded to magnetization from an MFM probe. This implied that Mn(2+) ions were incorporated within the Zn1-xMnxTe NCs and gave rise to the diluted magnetic semiconductor (DMS) structure. The PL spectra not only confirmed the evidence obtained by OA, CFT, TEM and AFM/MFM, but also showed that Mn(2+) concentration could be used to tune (4)T1((4)G) → (6)A1((6)S) emission energy.
我们研究了锰（Mn）浓度对通过熔融法在玻璃基质中生长的Zn1-xMnxTe纳米晶（NCs）的光学、形态和磁性的影响。这些材料的物理性质通过光吸收（OA）、透射电子显微镜（TEM）、原子/磁力显微镜（AFM/MFM）和光致发光（PL）来确定。基于晶体场理论（CFT）对OA光谱的分析有力地表明，Mn(2+)离子以替代方式掺入Zn1-xMnxTe纳米晶中，直至达到溶解度极限（浓度，x = 0.100）。高于此标称浓度时，TEM显示在PZABP玻璃系统中出现了与Mn相关的相，如MnO和α-MnO2。AFM图像显示，随着x含量的增加，玻璃基质表面的纳米晶密度降低。在较高浓度下，MnO和MnO2纳米晶的数量可能会超过Zn1-xMnxTe纳米晶——这一结论得到了OA光谱和TEM图像的证实。MFM图像显示，含有Mn(2+)离子的样品对MFM探针的磁化有响应。这意味着Mn(2+)离子掺入了Zn1-xMnxTe纳米晶中，并产生了稀磁半导体（DMS）结构。PL光谱不仅证实了通过OA、CFT、TEM和AFM/MFM获得的证据，还表明Mn(2+)浓度可用于调节(4)T1((4)G) → (6)A1((6)S)发射能量。
