Department of Physics, National Taiwan University, Taipei, Taiwan.
Nanotechnology. 2011 Mar 25;22(12):125701. doi: 10.1088/0957-4484/22/12/125701. Epub 2011 Feb 14.
An on-chip approach for fabricating ferromagnetic/semiconductor-nanotip heterojunctions is demonstrated. The high-density array of Si nanotips (SiNTs) is employed as a template for depositing La(0.7)Sr(0.3)MnO(3) (LSMO) rods with a pulsed-laser deposition method. Compared with the planar LSMO/Si thin film, the heterojunction shows a large enhancement of room temperature magnetoresistance (MR) ratio up to 20% under 0.5 T and a bias current of 20 µA. The MR ratio is found to be tunable, which increases with increasing external bias and the aspect ratios of the nanotips. Electric-field-induced metallization, in conjunction with nanotip geometry, is proposed to be the origin for the giant MR ratio.
本文展示了一种用于制造铁磁体/半导体-纳米尖异质结的片上方法。高密度的硅纳米尖（SiNTs）阵列被用作用脉冲激光沉积法沉积 La(0.7)Sr(0.3)MnO(3)（LSMO）棒的模板。与平面 LSMO/Si 薄膜相比，在 0.5 T 和 20 µA 的偏置电流下，异质结在室温下的磁电阻（MR）比高达 20%，并且该 MR 比可以通过增加外部偏置和纳米尖的纵横比来进行调节。提出电场诱导的金属化与纳米尖几何形状相结合是产生巨大 MR 比的原因。
