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Synthesis, crystal growth and characterization of phosphides, selenides, sulfides and oxides.

机译:磷化物,硒化物,硫化物和氧化物的合成,晶体生长和表征。

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摘要

The desire to build smaller, faster, inexpensive electronics has prompted researchers to exploit electron "spin" in transistors. Spin in semiconductors offers a pathway towards integration of storage and processing in a single material. These "spintronic" transistors could be highly energy-efficient and perform more computations than traditional transistors in a smaller space. In addition, in optoelectronic applications, lasers and light-emitting diodes that take advantage of electron spin could increase the data-carrying capacity of light. But one of the key hurdles in this emerging field is that the magnetic and semiconducting materials needed to make a spintronic device are notoriously incompatible. We have focused on different oxides, phosphides and sulfides to study crystal growth and properties of spintronics.;We have reported the synthesis of pure ZnO and Mn substituted ZnO crystals from sodium hydroxide and potassium hydroxide flux for the first time. Various oxides, including boron oxide (B2O3), vanadium oxide (V2O5), tungsten oxide (WO3) and molybdenum oxide (MoO3), were also used for crystal growth. A non-uniform distribution of Mn substitution was found in ZnO single crystals, and 3 at.% Mn concentration was identified. In addition, polycrystalline Mn-substituted ZnO powder samples exhibited solubility of Mn in the ZnO lattice. SQUID magnetic properties investigation of Mn-substituted polycrystalline samples indicated paramagnetism down to 5 K.;We have also investigated phosphides, selenides, and sulfides for spintronic applications, based on the well-studied spintronic material, gallium arsenide (GaAs), with a Curie temperature of 110K. GaAs has the zincblende structure with Ga in tetrahedral coordination. ZnSiP2, CdSiP2, KGaS 2 and KGaSe2 have metal atoms in tetrahedral coordination with no localized spin. Localized spin will be present if transition metals are substituted in. The synthesis of single phase ZnSiP2 and CdSiP 2 were grown from two different heat treatments. Also, potassium gallium selenide (KGaSe2) and potassium gallium sulfide (KGaS2) were reported. Temperature dependence susceptibility data revealed a ferromagnetic transition near 300 K followed by an antiferromagnetic transition near 50 K. Hysteresis loops at room temperature were present in all Mn substituted samples. Magnetic properties of Mn substituted samples are comparable with the crystalline MnP sample; they remain unidentified in X-ray diffraction data.
机译:建立更小,更快,更便宜的电子产品的愿望促使研究人员开发晶体管中的电子“自旋”。旋入半导体为整合单一材料中的存储和加工提供了一条途径。与传统晶体管相比,这些“自旋电子”晶体管在较小的空间内可能具有很高的能效,并且可以执行更多的计算。另外,在光电应用中,利用电子自旋的激光器和发光二极管可以增加光的数据传输能力。但是,这个新兴领域的主要障碍之一是众所周知,制造自旋电子器件所需的磁性材料和半导体材料不兼容。我们研究了不同的氧化物,磷化物和硫化物,以研究自旋电子学的晶体生长和性能。我们首次报道了由氢氧化钠和氢氧化钾助熔剂合成纯ZnO和Mn取代的ZnO晶体。各种氧化物,包括氧化硼(B2O3),氧化钒(V2O5),氧化钨(WO3)和氧化钼(MoO3),也用于晶体生长。在ZnO单晶中发现了Mn取代的不均匀分布,并确定了3 at。%的Mn浓度。另外,多晶Mn取代的ZnO粉末样品表现出Mn在ZnO晶格中的溶解度。 Mn取代的多晶样品的SQUID磁性研究表明,顺磁性可低至5 K .;我们还研究了自旋电子学应用中的磷化物,硒化物和硫化物,它基于经过充分研究的自旋电子学材料砷化镓(GaAs)和居里温度为110K。 GaAs具有四面体配位的Ga的锌闪锌矿结构。 ZnSiP2,CdSiP2,KGaS 2和KGaSe2具有四面体配位的金属原子,没有局部自旋。如果过渡金属被取代,则会出现局部自旋。单相ZnSiP2和CdSiP 2的合成是通过两种不同的热处理方法生长的。另外,还报告了硒化钾镓(KGaSe2)和硫化钾镓(KGaS2)。温度依赖性磁化率数据显示,在300 K附近发生铁磁转变,然后在50 K附近发生反铁磁转变。所有Mn取代样品中均存在室温下的磁滞回线。 Mn取代样品的磁性与结晶MnP样品相当。它们在X射线衍射数据中仍然不确定。

著录项

  • 作者

    Feng, Chun-Min.;

  • 作者单位

    City University of New York.;

  • 授予单位 City University of New York.;
  • 学科 Chemistry Inorganic.;Engineering Materials Science.;Physics Condensed Matter.
  • 学位 Ph.D.
  • 年度 2010
  • 页码 227 p.
  • 总页数 227
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:36:54

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