Formation of SmCo5 single-crystal submicron flakes and textured polycrystalline nanoflakes
Formation of SmCo5 single-crystal submicron flakes and textured polycrystalline nanoflakes
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DOI：
10.1016/j.actamat.2010.09.060
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发表时间：
2011-01-01
期刊：
影响因子：
9.4
通讯作者：
Hadjipanayis, G. C.
中科院分区：
文献类型：
--
作者：
Cui, B. Z.;Li, W. F.;Hadjipanayis, G. C.
表面活性剂辅助高能球磨（HEBM）的可延展材料已被发现导致薄片的形成。然而，SmCo 5磁性材料本身是脆性的，因此，在球磨过程中预计不会“剥落”。在这项研究中，我们报告了具有亚微米厚度的高纵横比单晶片和具有亚微米或纳米尺寸厚度的织构多晶SmCo 5片的一步表面活性剂辅助HEBM在庚烷中的制备，庚烷中含有15 wt.%油酸在HEBM的第一阶段，单晶微米片首先通过沿初始不规则且大的单晶颗粒的易滑移（0 0 1）面的基底解理沿着形成。随后，通过连续分裂形成单晶亚微米薄片。随着进一步球磨，形成具有小角度晶界的多晶亚微米薄片。最后，得到了具有[0 0 1]面外织构、厚度为6-80 nm、平均晶粒尺寸为7-8 nm、纵横比为10（2）~ 10（3）、折射率为16.3-17.7 kOe的多晶SmCo 5纳米片。负责不寻常的形成单晶亚微米片和各向异性纳米晶纳米片的机制进行了讨论，从初始固有的脆性多晶锭与不规则的晶粒尺寸为几十微米。(C)2010 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
Surfactant-assisted high-energy ball milling (HEBM) of malleable materials has been found to lead to the formation of flakes. However, SmCo5 magnetic materials are inherently brittle and, therefore, are not expected to "flake" during ball milling. In this study, we report the fabrication of high-aspect-ratio single-crystal flakes with a submicron thickness and textured polynanocrystalline flakes with a submicron or nanosize thickness of SmCo5 by one-step surfactant-assisted HEBM in heptane with 15 wt.% oleic acid. Single-crystal micron flakes were first formed via a basal cleavage along the easy glide (0 0 1) planes of the initial irregular and large single-crystal particles during the first stage of HEBM. Subsequently, single-crystal submicron flakes were formed by continuous cleavage. With further ball milling, polycrystalline submicron flakes with small-angle grain boundaries were formed. Finally, crystallographically anisotropic polycrystalline SmCo5 nanoflakes were formed with [0 0 1]-out-of-plane texture, thicknesses of 6-80 nm, average grain sizes of 7-8 nm, an aspect ratio of 10(2)-10(3) and coercivities of 16.3-17.7 kOe. The mechanism responsible for unusual formation of single-crystal submicron flakes and anisotropic nanocrystalline nanoflakes from initial inherently brittle polycrystalline ingots with irregular grains of tens of microns in size is discussed. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.