Magnetic and transport properties of homogeneous MnxGe1−x ferromagnetic semiconductor with high Mn concentration
作者:Y. X. Chen、Shi-shen Yan、Y. Fang、Y. F. Tian、S. Q. Xiao、G. L. Liu、Y. H. Liu、L. M. Mei
DOI:10.1063/1.2436710
日期:2007.1.29
HomogeneousMnxGe1−xferromagneticsemiconductor films with highMnconcentration were prepared, contrasting with dilute inhomogeneous MnxGe1−xmagneticsemiconductors. The saturation magnetization of Mn0.57Ge0.43 films is high, up to 327emu∕cm3 (1.04μB∕Mn) at 5K, and the Curie temperature is about 213K. The Mn0.57Ge0.43 films show semiconducting resistance, but the magnetoresistance is negligibly
Magneto-optical and magnetotransport properties of amorphous ferromagnetic semiconductor Ge1−xMnx thin films
作者:Shinsuke Yada、Satoshi Sugahara、Masaaki Tanaka
DOI:10.1063/1.3023070
日期:2008.11.10
The authors investigate the magnetooptical and magnetotransportproperties of Mn-doped amorphous Ge (a-Ge1−xMnx) thinfilms deposited on thermally oxidized Si substrates. Magnetic circular dichroism measurements reveal that their ferromagnetic ordering appears for x>0.02 and the films show magnetically homogeneous behavior. The resistivity of the films decreases with increasing x, and the temperature
作者研究了沉积在热氧化硅衬底上的 Mn 掺杂非晶 Ge (a-Ge1-xMnx) 薄膜的磁光和磁传输特性。磁性圆二色性测量表明,当 x>0.02 时它们的铁磁有序出现,并且薄膜显示出磁性均匀的行为。薄膜的电阻率随着 x 的增加而降低,并且电阻率的温度依赖性显示出类似半导体的行为。a-Ge1-xMnx 薄膜的异常霍尔效应也表现出铁磁行为。磁化的温度依赖性与磁光和磁传输结果的温度依赖性一致。这些结果表明 a-Ge1-xMnx 薄膜表现为铁磁半导体。
Strong anisotropy of magnetization and sign reversion of ordinary Hall coefficient in single crystal Ge1−xMnx magnetic semiconductor films
作者:J. X. Deng、Y. F. Tian、S. M. He、H. L. Bai、T. S. Xu、S. S. Yan、Y. Y. Dai、Y. X. Chen、G. L. Liu、L. M. Mei
DOI:10.1063/1.3206664
日期:2009.8.10
single-crystal Ge1−xMnx ferromagnetic-semiconductor films were fabricated on Ge(001) substrates by molecular beam epitaxy. All the samples are ferromagnetic and have strongmagneticanisotropy indicated by different magnetization in plane and out of plane. The electrical transport of the films obeys Efros variable range hopping law in the low temperature range. Interestingly, a negative coefficient of the
We have grown MnxGe1-x films (x=0, 0.06, 0.1) on Si (001) substrates by magnetron cosputtering, and have explored the resulting structural, morphological, electrical and magnetic properties. X-ray diffraction results show there is no secondary phase except Ge in the Mn0.06Ge0.94 film while new phase appears in the Mn0.1Ge0.9 film. Nanocrystals are formed in the Mn0.06Ge0.94 film, determined by field-emission scanning electron microscopy. Hall measurement indicates that the Mn0.06Ge0.94 film is p-type semiconductor and hole carrier concentration is 6.07 X 10(19) cm(-3) while the MnxGe1-x films with x=0 has n-type carriers. The field dependence of magnetization was measured using alternating gradient magnetometer, and it has been indicated that the Mn0.06Ge0.94 film is ferromagnetic at room temperature. (c) 2005 Elsevier Ltd. All rights reserved.
Local chemical distribution and electronic structure of Ge1−T DMS single crystals (T=Cr, Mn, Fe)
作者:J.-S. Kang、G. Kim、S.S. Lee、S. Choi、S. Cho、S.W. Han、H.J. Shin、B.I. Min
DOI:10.1016/j.jmmm.2006.02.036
日期:2006.9
The spatial concentration distribution and local electronic structure of ferromagnetic Ge1-xTx (T = Cr, Mn, Fe) DMS single crystals have been investigated by using scanning photoelectron microscopy (SPEM), X-ray absorption spectroscopy (XAS), and photoemission spectroscopy (PES). It is found that doped T ions in Ge1-xTx crystals are chemically phase-separated, suggesting that the observed ferromagnetism arises from the phase-separated T-rich phases in Ge1-xTx. (C) 2006 Elsevier B.V. All rights reserved.