Phase Segregation of MnP in Chalcopyrite Dilute Magnetic Semiconductors: A Cautionary Tale

详细信息    查看全文

• 作者：Jennifer A. Aitken ; Georgiy M. Tsoi ; Lowell E. Wenger ; Stephanie L. Brock
• 刊名：Chemistry of Materials
• 出版年：2007
• 出版时间：October 30, 2007
• 年：2007
• 卷：19
• 期：22
• 页码：5272 - 5278
• 全文大小：295K
• 年卷期：v.19,no.22(October 30, 2007)
• ISSN：1520-5002

文摘

On the basis of reports of room-temperature ferromagnetism in Mn-doped semiconductor chalcopyrites,we undertook an investigation of a new doped system, CdSnP₂:Mn. CdSnP₂ heated with Mn powder ina tube furnace under flowing argon at 350 and 500 C resulted in a material having ferromagnetic properties(T_c 290 K) closely resembling those reported for other Mn-doped chalcopyrites (e.g., CdGeP₂, ZnGeP₂).However, the appearance of weak MnP impurity peaks in the powder X-ray diffraction pattern for the500 C prepared sample, coupled with the strong similarity in the measured ferromagnetic behaviors,suggests that the ferromagnetic response may not be an intrinsic effect. Measurements on bulk andnanocrystalline MnP as well as on control samples prepared by heating CdP₂ or red phosphorus with Mnpowder lead to the conclusion that (i) heating mixtures of CdSnP₂ with Mn results in phase-segregatedMnP, a room-temperature ferromagnetic material, and (ii) amounts as small as 0.3 wt % (1.0 mol %)MnP, well below the resolution of powder X-ray diffraction, are sufficient to dominate the magneticresponse in these chalcopyrite materials.