Synthesis of crystallite-dispersed nano-composites by ion implantation into amorphous alloys

研究了离子注入诱导非晶合金局部晶化在制备晶/非晶纳米复合材料中的应用。使用氦离子作为注入物质，因为它们在化学上最不活跃。在靶材方面，以Fe-B-B和Fe-Si-B合金作为金属-类金属型非晶合金的代表，以Fe-Zr合金作为典型的金属-金属型非晶合金。在安装了精确控制注入温度的装置后，对Fe-B合金样品进行了预处理。然而，由于离子注入器的故障，无法系统地制备注入样品。结果表明：（1）Fe-B合金的诱导晶化量随剂量的增加而增加，在高剂量时达到饱和;剂量依赖性通过降低注入温度而变得缓和使得该量变得很好地可控，2）如果剂量低于结晶的临界剂量，则在注入后的局部结构和热稳定性中没有观察到显著变化，3）当诱导结晶相的量小时，结晶细颗粒与残余的非晶相磁性隔离，4）结晶细颗粒似乎通过整合相邻颗粒而生长，这对于本发明的目的是不利的，因为结晶颗粒的量和尺寸不能独立控制。将尽快报告与Fe-Si-B和Fe-Zr结果的比较。

The applicability of ion-implantation induced local crystallization of amorphous alloys to the synthesis of crystal/amorphous nano-composites was studied. Helium ions were used as implant species since they are chemically most inactive. For target materials, Fe-B and Fe-Si-B alloys were used as representatives of metal- metalloid type amorphous alloys, whereas Fe-Zr alloy was selected as typical metal-metal type amorphous alloy. After installing a unit for precision control of implantation temperature, implantations were conducted on Fe-B alloy samples. However, systematic preparation of implanted samples was not possible due to the malfunction of the ion implanter. Thus the following were concluded from the results only on Fe-B alloys: 1) the amount of induced crystalline phase increases with increasing dose and saturates at high doses; the dose dependence becomes moderated by lowering implantation temperature so that the amount becomes well controllable, 2) no significant change is observed in local structure and in thermal stability after implantation if doses are below the critical dose for crystallization, 3) when the amount of induced crystalline phase is small, crystalline fine particles are magnetically isolated from the residual amorphous phase(s), 4) crystalline fine particles seems to grow by integrating neighboring parlicles, which are unfavorable for the present purpose because amount and size of crystalline particles cannot be controlled independently. The comparison with the results for Fe-Si-B and Fe-Zr will be reported as soon as possible.