Electron Spin Resonance and Electron Nuclear Double Resonance Studies of Ion-irradiated Synthetic Diamond Crystals

为了开发钻石的应用，需要加入新的杂质来产生有用的特性。我们探索了利用高能离子辐照作为一种新的弥散杂质掺入金刚石的方法的条件。对于不同杂质(N，B，Ni)的H^+注入，用10 MeV的H^+离子轰击各种合成晶体，注量从1×10^~1×10^/cm2到1×10^&lt；17&gt；/cm^2。研究发现，不同类型的金刚石晶体产生的注入缺陷种类不同。结果表明，空位相关缺陷的ESR信号强度在高通量下有饱和的趋势，在金刚石中可能存在n型掺杂。用电子自旋共振技术研究了高能(9-18 MeV)磷离子注入IIa型高压人造金刚石晶体。ESR信号的强度和线宽随注入剂量的不同而变化，表明非晶化的性质随注入剂量的不同而不同。在低剂量注入晶体和高温高压退火的高剂量晶体中观察到了点缺陷的ESR信号。正在对可能由磷相关缺陷引起的ESR信号进行详细的单晶测量，包括Endor。

To develop applications of diamond, incorporation of new impurities which create useful properties is required. We have searched conditions for utilizinf high-energy ion-irradiation as a method of incorporating new dispersed impurities into diamond.For the H^+ implantation, various synthetic crystasls with various concentrations of impurities (N,B,Ni) were bombarded with 10 MeV H^+ ion with a fluence 1*10^<15>/cm^2 to 1*10^<17>/cm^2. After H^+-implantation, several kinds of electron spin resonance (ESR) signals which are arising from vacancy-related defects were observed. It has been found that the kinds of implantation-induced defects are different among the different types of diamond crystals. It is noted that the increase of the ESR signal intensities of vacancy-related defects has a tendency of saturation at higher fluences.Phoshorus is among potential n-type dopants in diamond. High pressure synthetic diamond crystals of type IIa implanted with high energy (9-18 MeV) phosphorus ions have been studied by using ESR techique. The intensity and the linewidth of the ESR signal attributed to the dangling bond of the amorphous phase which was fromed as radiation damage varied with the implantation dose, suggesting the nature of the amorphization varies with the dose. The ESR signals of point defects have been observed in the low dose as-implanted crystals and in the high dose crystals annealed at high temperature and at high pressure. Detailed single srystal measurements inclueding ENDOR are being carried out for the ESR signals which might be arising from phosphorus-related defects.