Review Article: FePt heat assisted magnetic recording media
Review Article: FePt heat assisted magnetic recording media
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DOI：
10.1116/1.4965980
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发表时间：
2016-11-01
影响因子：
1.4
通讯作者：
Albrecht, Manfred
中科院分区：
文献类型：
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作者：
Weller, Dieter;Parker, Gregory;Albrecht, Manfred
热辅助磁记录（HAMR）介质的现状、要求和挑战，以将磁硬盘驱动器的面密度（AD）扩展到超过约1.4 Tb/in的当前记录。(2)已更新。颗粒状高各向异性化学有序L1（0）FePtX-Y HAMR磁记录介质的结构特性与垂直CoCrPt基磁记录介质相似。尽管< D >生长温度T-G = 650-670 ℃，但合理的平均晶粒直径= 8-10 nm和分布σ（D）/D类似于18%是可能的。降低2倍< D >至4-5 nm和降低sigma（D）/D < 10%-15%是将AD增加至类似于4 Tb/in的持续努力。（二）、X = Cu，类似于10 at. %将居里温度T-C降低了类似于低于T-C的100 K，T-bulk = 750 K，从而降低了写入头热能需求。具有Y = 30-35体积%的晶粒间偏析物（如碳化物、氧化物和/或氮化物）的多个FePtX-Y颗粒层用于完全交换解耦晶粒并实现圆柱形形状。FePt通常生长在fcc MgO（100）晶种层上以形成良好取向的FePt（002）。类似于0.96的FePt晶格参数比c/a和高化学有序S > 0.90导致磁各向异性K-U类似于4.5 × 10（7）erg/cm（3），并且在7-8 nm直径的晶粒中仅比FePt单晶值K-U = 6.6 × 10（7）erg/cm（3）低25%。开关场分布取决于各向异性场（H-K）分布，其目前在室温下具有类似于10%的Δ H-K/H-K的量级（Δ H-K类似于10-12 kOe，H-K类似于10-11 T）。包括Ag、Au、Cu和Cr的高热导率散热层用于优化冷却速率并使向下和跨轨道的热梯度最大化，这决定了可实现的轨道密度。(C)2016年作者。
Heat-assisted magnetic recording (HAMR) media status, requirements, and challenges to extend the areal density (AD) of magnetic hard disk drives beyond current records of around 1.4 Tb/in.(2) are updated. The structural properties of granular high anisotropy chemically ordered L1(0) FePtX-Y HAMR media by now are similar to perpendicular CoCrPt-based magnetic recording media. Reasonable average grain diameter < D > = 8-10 nm and distributions sigma(D)/D similar to 18% are possible despite elevated growth temperatures T-G = 650-670 degrees C. A 2 x reduction of < D > down to 4-5 nm and lowering sigma(D)/D < 10%-15% are ongoing efforts to increase AD to similar to 4 Tb/in.(2). X = Cu similar to 10 at. % reduces the Curie temperature T-C by similar to 100K below T-C,T-bulk = 750 K, thereby lowering the write head heat energy requirement. Multiple FePtX-Y granular layers with Y = 30-35 vol. % grain-to-grain segregants like carbides, oxides, and/or nitrides are used to fully exchange decouple the grains and achieve cylindrical shape. FePt is typically grown on fcc MgO (100) seedlayers to form well oriented FePt (002). A FePt lattice parameter ratio c/a similar to 0.96 and high chemical order S > 0.90 result in magnetic anisotropy K-U similar to 4.5 x 10(7) erg/cm(3), and only 25% below the FePt single crystal value K-U = 6.6 x 10(7) erg/cm(3) has been achieved in 7-8 nm diameter grains. Switching field distributions depend on anisotropy field (H-K) distributions, which are currently of the order of Delta H-K/H-K similar to 10% (Delta H-K similar to 10-12 kOe, H-K similar to 10-11 T) at room temperature. High thermal conductivity heat sink layers, including Ag, Au, Cu, and Cr, are used to optimize the cooling rate and maximize the down-and cross-track thermal gradient, which determines the achievable track density. (C) 2016 Author(s).