title: Superlattice of Fe(x)Ge(1-x) nanodots and nanolayers for spintronics application.
abstract: Fe(x)Ge(1-x) superlattices with two types of nanostructures, i.e. nanodots and nanolayers, were successfully fabricated using low-temperature molecular beam epitaxy. Transmission electron microscopy (TEM) characterization clearly shows that both the Fe(x)Ge(1-x) nanodots and nanolayers exhibit a lattice-coherent structure with the surrounding Ge matrix without any metallic precipitations or secondary phases. The magnetic measurement reveals the nature of superparamagnetism in Fe(x)Ge(1-x) nanodots, while showing the absence of superparamagnetism in Fe(x)Ge(1-x) nanolayers. Magnetotransport measurements show distinct magnetoresistance (MR) behavior, i.e. a negative to positive MR transition in Fe(x)Ge(1-x) nanodots and only positive MR in nanolayers, which could be due to a competition between the orbital MR and spin-dependent scatterings. Our results open a new growth strategy for engineering Fe(x)Ge(1-x) nanostructures to facilitate the development of Ge-based spintronics and magnetoelectronics devices.
authors.affiliation: Device Research Laboratory, Department of Electrical Engineering, University of California, Los Angeles, California, USA, 90095.
authors.forename: Tianxiao
authors.initials: T
authors.lastname: Nie
authors.forename: Xufeng
authors.initials: X
authors.lastname: Kou
authors.forename: Jianshi
authors.initials: J
authors.lastname: Tang
authors.forename: Yabin
authors.initials: Y
authors.lastname: Fan
authors.forename: Murong
authors.initials: M
authors.lastname: Lang
authors.forename: Li-Te
authors.initials: LT
authors.lastname: Chang
authors.forename: Chia-Pu
authors.initials: CP
authors.lastname: Chu
authors.forename: Liang
authors.initials: L
authors.lastname: He
authors.forename: Sheng-Wei
authors.initials: SW
authors.lastname: Lee
authors.forename: Faxian
authors.initials: F
authors.lastname: Xiu
authors.forename: Jin
authors.initials: J
authors.lastname: Zou
authors.forename: Kang L
authors.initials: KL
authors.lastname: Wang