Effect of Defects on Magnetic Properties of O^(+) -implanted AlN Films by Positron Annihilation Spectroscopy  

正电子湮没谱学研究氧离子注入AlN薄膜中缺陷对磁性影响

作　　者：YE Run YE Bangjiao 叶润;叶邦角(盐城师范学院物理与电子工程学院,江苏盐城224007;中国科学技术大学核探测与核电子学国家重点实验室,合肥230026)

机构地区：[1]School of Physics and Electronic Engineering,Yancheng Teachers University,Yancheng 224007,Jiangsu,China [2]State Key Laboratory of Particle Detection and Electronics,University of Science and Technology of China,Hefei 230026,China

出　　处：《原子核物理评论》2024年第1期498-503,共6页Nuclear Physics Review

基　　金：国家重点研发计划“纳米科技”重点专项资助项目(2019YFA0210000);国家自然科学基金资助项目(12305333);核探测与核电子学国家重点实验室开放课题资助项目(SKLPDE-KF-202114);盐城市基础研究计划资助项目(YCBK2023061);江苏省“双创博士”计划资助项目(JSSCBS20211148);江苏省自然科学基金资助(BK20220699)。

摘　　要：Room-temperature ferromagnetism is observed in the O^(+)-implanted AIN films with O+doses of 5×10^(16) cm^(-2)(AIN:Osxion)and 2×10^(17) cm^(-2)(AIN:O_(2x1on)).The observed magnetic anisotropy indicates that the ferromagnetism is attributed to the intrinsic properties of O^(+) -implanted AIN films.The out-of-plane saturation magnetization(Ms)of the AIN:O5×10^(16) is about 0.68 emu/g,much higher than that of AIN:O_(2x1017),0.09 emu/g,which is due to the excessively high O^(+)dose made more O+ions occupy adjacent A1^(3+)positions in forms of antiferromagnetic coupling.Doppler broadening of positron annihilation radiation measurements demonstrate the existence of Al vacancies in the O^(+)-implanted AIN films.The first-principles calculations suggest that the ferromagnetism originates mainly from the Al vacancies.Meanwhile,the formation of divacancies or vacancy clusters by high concentrations of Al vacancies will lead to the transformation of VA-VAi coupling from ferromagnetim to antiferromagnetism,ultimately weakening the ferromagnetism of the sample.在氧离子注入的AIN薄膜AIN:0_(5×10^(16))(剂量为5×10^(16)cm^(-2))和AIN:O_(2×10^(17))(剂量为2×10^(17)cm^(-2))中观察到了室温铁磁性。所观察到的磁各向异性表明,氧离子注入的AIN薄膜中铁磁性是本征特性。在垂直于样品平面的外加磁场下,AIN:O5x101中的饱和磁化强度约为0.68emu/g,高于AIN:O_(2×10^(17))中的饱和磁化强度0.09emu/g。这是由于过高的氧离子剂量使得更多的氧离子占据相邻的A1离子位置,导致了反铁磁耦合的出现。正电子没多普勒展宽谱表明在氧离子注入的AIN薄膜中存在大量的AI空位。第一性原理计算表明氧离子注入的AIN薄膜中的铁磁性主要来源于AI空位,而高浓度的AI空位形成双空位或空位团将会使得AIN样品从铁磁性到反铁磁性转变,最终使样品的铁磁性减弱。

关 键 词：positron annihilation spectroscopy ion implantation SEMICONDUCTORS FERROMAGNETISM 

分 类 号：O771[理学—晶体学]