Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Strain-induced high ferromagnetic transition temperature of MnAs epilayer grown on GaAs (110) | Xu et al. Nanoscale Research Letters 2011 6 125 http content 6 1 125 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Strain-induced high ferromagnetic transition temperature of MnAs epilayer grown on GaAs 110 1 1 1 1 1 f n 2 1 Pengfa Xu Jun Lu Lin Chen Shuai Yan Haijuan Meng Guoqiang Pan Jianhua Zhao Abstract MnAs films are grown on GaAs surfaces by molecular beam epitaxy. Specular and grazing incidence X-ray diffractions are used to study the influence of different strain states of MnAs GaAs 110 and MnAs GaAs 001 on the first-order magnetostructural phase transition. It comes out that the first-order magnetostructural phase transition temperature Tt at which the remnant magnetization becomes zero is strongly affected by the strain constraint from different oriented GaAs substrates. Our results show an elevated Tt of 350 K for MnAs films grown on GaAs 110 surface which is attributed to the effect of strain constraint from different directions. PACS Introduction Today there is growing interest for realization of new technologies utilizing spin degree of freedom of electrons in semiconductor devices 1 . The technology of manipulating spin in semiconductors promises devices with enhanced functionality and higher speed. A prerequisite for realization of such kind of devices is development of solid-state spin injectors at room temperature. Diluted magnetic semiconductors DMSs and ferromag-net semiconductor hybrids are two important components for efficient spin injection. The exploitation of DMSs however is severely hindered by their low Curie temperature due to the low solubility of transition metals in semiconductors 2 3 . With room-temperature ferromagnetism and high crystal quality MnAs has been epitaxied on 001 - 110 - 111 - and 113 -oriented GaAs substrates 4-9 . Moreover MnAs GaAs having sharper interface than that of Fe GaAs has been presented 10 11 the sharp interface is .
