Ferromagnetism in Ge/SiO2 multilayer films

被引：4

作者：

Zhen, Congmian ^{[1
]}

Liu, Yuanbo ^{[1
]}

Ma, Li ^{[1
]}

Pang, Zhaoguang ^{[1
]}

Pan, Chengfu ^{[1
]}

Hou, Denglu ^{[1
]}

机构：

[1] Hebei Normal Univ, Hebei Adv Thin Films Lab, Inst Phys, Shijiazhuang 050016, Peoples R China

来源：

JOURNAL OF APPLIED PHYSICS | 2010年 / 107卷 / 04期

基金：

美国国家科学基金会;

关键词：

amorphous magnetic materials; amorphous semiconductors; bonds (chemical); diamagnetic materials; elemental semiconductors; ferromagnetic materials; germanium; magnetic domains; magnetic multilayers; magnetic structure; magnetic thin films; photoluminescence; semiconductor thin films; silicon compounds; size effect; QUANTUM DOTS; PHOTOLUMINESCENCE; SIO2; NANOCRYSTALS; MAGNETISM; OXIDE;

D O I：

10.1063/1.3294621

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

The onset of room-temperature (RT) ferromagnetism (FM) has been experimentally observed in amorphous Ge/SiO2 multilayer films. Both the thickness of the individual layers of SiO2 and that of the Ge layers can influence the ferromagnetic order of the samples. The saturation magnetization (M-S) reached a maximum of 18.3 emu/cm(3) at RT for the film with structure [Ge(5 nm)/SiO2(8 nm)](3). The zero-field-cooled and field-cooled curves for the film show the coexistence of ferromagnetic and diamagnetic components. Obvious magnetic domains were observed in all of the samples. Ge forms mainly Ge-Ge bonds. In addition, Photoluminescence from interband indirect recombination and transitions between discrete energy levels in Ge nanostructures were observed. The FM in the Ge/SiO2 multilayer films can be attributed to both the quantum size effect and coupling of unpaired spins among the Ge nanostructures. The coupling tends to make the unpaired spins align in a ferromagnetic manner.

引用

页数：5

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