MAT science Week

Mn doped III-V compounds semiconductors have been regarded as the prototype of ferromagnetic semiconductors. However, their preparation presents a big challenge due to the low solubility of Mn. In this talk, I will show how ion beams can be used in fabricating and understanding ferromagnetic semiconductors. First, ion implantation followed by pulsed laser melting (II-PLM) provides an alternative to the widely used low-temperature molecular beam epitaxy approach [1]. II-PLM is successful to bring two new members, GaMnP and InMnP, into the family of III-V:Mn [2]. For the first time, we could prepare GaMnAs and InMnAs with low Mn concentration to cross over the insulator-to-metal transition regime [3]. Second, we use helium ion to precisely compensate hole in ferromagnetic semiconductors while keeping the Mn concentration constant [4]. These materials synthesized or tailored by ion beams provide an alternative avenue to understand how carrier-mediated ferromagnetism is influenced by localization. [1] M. Scarpula, et al. PRL 95, 207204 (2005), S. Zhou, et al., APEX 5, 093007 (2012), S. Zhou, JPD 48, 263001 (2015). [2] M. Khalid et al., PRB 89, 121301(R) (2014), Y. Yuan et al., IEEE Trans. Magn. 50, 2401304 (2014). [3] S. Prucnal et al., PRB 92, 224407 (2015), Y. Yuan et al., PRM 1, 054401 (2017). [4] L. Li, et al., JPD 44 099501 (2011), L. Li, et al., NIMB 269, 2469 (2011), S. Zhou, et al., PR B 95, 075205 (2016), Y. Yuan et al., JPD in press (2018).