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Study on the Magnetic Properties of Mn-doped Ge/Si Based Diluted Magnetic Semconductor Films

Author: QiaoShuang
Tutor: HouDengLu
School: Hebei Normal
Course: Condensed Matter Physics
Keywords: Hall effect The morphology and magnetic domain Diluted magnetic semiconductors Ferromagnetic
CLC: O484.43
Type: Master's thesis
Year: 2009
Downloads: 56
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Abstract

In the modern information technologies, the information processing is realized by controlling the charge of the electron, and the storage of information is implemented by controlling the electron's spin. If you can use both of the charge and spin of the electron carrier, can lead to a new information processing and information storage. Dilute magnetic semiconductor materials while taking advantage of the electron spin and charge, with the charge transport properties of semiconductor materials and magnetic materials information storage characteristics, is a new type of functional materials. Due to the incorporation of the magnetic properties of transition metals or rare earth elements, and compared to traditional semiconductor dilute magnetic semiconductors has some strange properties. In this article, we prepared by magnetron sputtering the series high Mn-doped nano-size the Mn _x Ge _1-x Mn _x Si _1-x composite nano-structure materials. Which the Mn _x the Ge _1-x divided into direct deposition and substrate heating deposition two series the Mn _x the Si _1-x is the direct deposition series. XRD results show that all the samples are, respectively, the performance of Ge / Si basic levy peak. The MFM measurements did not reveal any significant magnetic domains, which implies that we prepared a sample does not exist possible strong magnetic clusters or granules. XPS measurements showed that Mn _x Ge _1-x series of samples in a zero-valent Mn in the 2 or 3 price Ge substrate; Mn _x Si < sub> 1-x series of samples, due to the interaction of Mn and Si lead to the binding energy peak bit is moved to the smaller direction. RT characterization of the resistivity of the sample is reduced with increasing temperature, showing obvious semiconductor characteristics. Hall effect measurements show that the room temperature samples showed normal Hall effect. And all the Mn _x Ge _1-x Mn _x the Si _-x samples are p-type semiconductor, The carrier concentration increases with the Mn atom content increases. The magnetic measurements show that the GE _{directly deposited Mn _{of x 1-x} samples exhibited low-temperature ferromagnetic heating deposition samples having ferromagnetism above room temperature. Its ferromagnetism by the exchange interaction of s, p-hole carrier and the d electrons of Mn atoms to produce the spin-orbit coupling and a hole carrier. Directly deposited Mn _{of x} Si _1-x sample has intrinsic ferromagnetism, its saturation magnetization with Mn concentration decreases, this hole carrier The carrier concentration change is opposite. Mn _x Si _1-x samples ferromagnetism by the long-range ferromagnetic exchange between the conduction electron and sparse distribution of Mn atoms interact to produce.}

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