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Fe-C-H_2O体系中金刚石成核特性

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Abstract:

用国产SPD6×1200型六面顶压机,在Fe粉末触媒和石墨(Fe-C)体系中添加不同比例的H2O,高温高压条件下合成出了金刚石单晶。通过扫描电子显微镜和Mossbauer谱研究了合成样品中金刚石的成核状态和Fe-C-H2O体系中H2O对金刚石成核的影响。结果表明在5.7GPa,1600℃条件下,当H2O的质量含量少于5%时,Fe-C-H2O体系可合成出金刚石;随着Fe-C-H2O体系中H2O含量的增加,样品中金刚石成核量逐渐减少;当H2O含量达到5%时,金刚石将不能成核生长。在合成过程中,Fe-C-H2O体系中的Fe与H2O首先发生氧化还原反应,生成FeO和FeHx。与Fe-C体系相比,H2O对金刚石成核具有明显的抑制作用,而且随着H2O含量的增加,抑制作用越明显。讨论了H2O对金刚石成核和生长抑制的机理。

References

[1]  BUNDY F P,HALL H T,STRONG H M,et al.Man made diamonds[J].Nature,1955,51:176-180. [2]BOVENKERK H P,BUNDY F P,HALL H T,et al.Preparation of diamond[J].Nature,1959,184:1094-1099. [3]AKAISHI M,KANDA H,YAMAOKA S.Synthesis of diamond from graphite carbonate system under very high temperature and pressure[J].J Cryst Growth,1990,104:578-581. [4]AKAISHI M,KANDA H,YAMAOKA S.Phosphorus:an elemental catalyst for diamond synthesis and growth[J].Science,1993,259:1592-1593. [5]AKAISHI M,KANDA H,YAMAOKA S.Morphology of synthetic diamond growth from Na2CO3solvent catalyst[J].J Cryst Growth,1990,106:471-475. [6]ZHOU Lin,JIA Xiaopeng,MA Hongan,et al.Influences of additive sulfur on the synthesis of industrial diamonds,using Ni70Mn25Co5alloy powder as catalyst[J].Diamond Relat Mater,2006,15:1318-1321. [7]LIANG Zhongzhu,KANDA H,JIA Xiaopeng,et al.Synthesis of diamond with high nitrogen concentration from powder catalyst-C-additive NaN3by HPHT[J].Carbon,2006,44:913-916. [8]QIN Jieming,MA Hongan,JIA Xiaopeng,et al.The effect of an iron powder catalyst clad with a Fe2O3layer on the nucleation of diamonds[J].Diamond Relat Mater,2006,15:1369-1372 [9]OKUCHI Takuo.The melting temperature of iron hydride at high pressures and its implications for the temperature of the earth’s core[J].J Phys:Condens Matter,1998,10:11595-11598. [10]FUKAI Y,MORI K,SHINOMIYA H.The phase diagram and supera-bundant vacancy formation in Fe-H alloy under high hydrogen pres-sures[J].J Alloys Compd,2003,348:105-109.

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