title: Structural transition from MgZnO nanowires to ultrathin nanowalls by surface separation: growth evolution and gas sensing properties.
abstract: This paper reports a spontaneous method of controlling the growth mode from vertically arrayed ultra-slim MgZnO nanowires to nanowalls through the in-plane random motion of the seed crystals formed by surface phase separation. Seed crystals with a relatively Zn-rich phase were formed by the simultaneous injection of Mg and Zn and became strongly networked when the Zn/Mg flux ratio was increased at high temperatures, leading to the formation of MgZnO nanowalls on various conducting substrates. The hydrogen sensing performance of the MgZnO nanowalls with a two-dimensional network structure was superior to that of the one-dimensional MgZnO nanowires. Based on the microstructural characterizations, the growth procedure for the structural transition from MgZnO nanowires to nanowalls on the Si substrates was proposed.
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Jangan-gu, Suwon, Gyeonggi-do, Republic of Korea.
authors.forename: Dong Chan
authors.initials: DC
authors.lastname: Kim
authors.forename: Ju Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Sanjay Kumar
authors.initials: SK
authors.lastname: Mohanta
authors.forename: Hyung Koun
authors.initials: HK
authors.lastname: Cho
authors.forename: Jeong Yong
authors.initials: JY
authors.lastname: Lee