High repetition granular Co/Pt multilayers with improved perpendicular remanent magnetization for high-density magnetic recording

作     者：李智 张昆 杜奥 张洪超 陈伟斌 徐宁 郝润润 颜世申 赵巍胜 冷群文 Zhi Li;Kun Zhang;Ao Du;Hongchao Zhang;Weibin Chen;Ning Xu;Runrun Hao;Shishen Yan;Weisheng Zhao;Qunwen Leng

作者机构：Fert Beijing Research Institute MIIT Key Laboratory of Spintronics School of Integrated Circuit Science and EngineeringBeihang UniversityBeijing 100191China Beihang–Goertek Joint Microelectronics Institute Qingdao Research Institute Beihang UniversityQingdao 266101China School of Physics State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2023年第32卷第2期

页      面：405-410页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant No. 51901008) the National Key Research and Development Program of China (Grant No. 2021YFB3201800) 

主　　题：granular Co/Pt multilayers perpendicular magnetic anisotropy remanent moment-thickness product magnetic recording 

摘      要：Thanks to the strong perpendicular magnetic anisotropy(PMA), excellent processing compatibility as well as novel spintronic phenomenon, Co/Pt multilayers have been attracting massive attention and widely used in magnetic ***, reversed magnetic domains come into being with the increasing layer repetition ‘N’ to reduce magneto-static energy, resulting in the remarkable diminishment of the remanent magnetization(Mr). As a result, the product of Mrand thickness(i.e., the remanent moment-thickness product, Mrt), a key parameter in magnetic recording for reliable data storing and reading, also decreases dramatically. To overcome this issue, we deposit an ultra-thick granular [Co/Pt]80multilayer with a total thickness of 68 nm on granular SiNxbuffer layer. The Mrt value, Mrto saturation magnetization(Ms) ratio as well as out of plane(OOP) coercivity(Hcoop) are high up to 2.97 memu/cm^(2), 67%, and 1940 Oe(1 Oe = 79.5775 A·m^(-1)),respectively, which is remarkably improved compared with that of continuous [Co/Pt]80multilayers. That is because large amounts of grain boundaries in the granular multilayers can efficiently impede the propagation and expansion of reversed magnetic domains, which is verified by experimental investigations and micromagnetic simulation results. The simulation results also indicate that the value of Mrt, Mr/Msratio, and Hcoopcan be further improved through optimizing the granule size, which can be experimentally realized by manipulating the process parameter of SiNxbuffer layer. This work provides an alternative solution for achieving high Mrt value in ultra-thick Co/Pt multilayers, which is of unneglectable potential in applications of high-density magnetic recording.