【摘要】 含铁绿松石的EPR波谱由不对称的Cu²⁺信号和对称的Fe³⁺信号叠加而成。首次测定了对称Fe³⁺信号的波谱参数,其各向同性g因子为2.006±0.002,常温△H_pp=100Gs。77K时增宽为610Gs。EPR定量分析指示:绿松石中Cu²⁺呈正常的顺磁性,而Fe³⁺大部分可能呈反铁磁性,只有小部分呈顺磁性,同时呈顺磁性的Fe³⁺不存在C.O.Clark等指出的在降温时向反铁磁性转化的效应。更多还原

【Abstract】 Several turquoise specimens with different contents of iron（0.5-8%）and different colours ranging from greyish blue to greyish yellow have been studied by electron paramagnetic resonance（EPR）and electron microprobe（EMP）.The copper ions in turquoise give an asymmetry EPR signal which provides the gfactors g₁=2.041±0.002, g₂=2.119±0.004, and g₃=2.324±0.004. The peak-to-peak linewidth of the Cu²⁺ signal is 80Gs for pure greyish blue sample. With the increase of Fe/Cu concentration ratio the shape of Cu²⁺ spectral line is broadened and deformed.The Fe³⁺ ions in turquoise give a symmetry EPR signal with the isotropic g-factor g=2.006±0.002. The peak-to-peak linewidth of the Fe³⁺ signal is 400 Gs at 20℃ and inerease to 610 Gs at 77K. Based on its temperature-dependence of linewidth, we regard the Clark’s conclusion that the ferric ions in turquoise behave antiferromagnetically at low temperature due to the temperature-dependence of the Fe³⁺ spectral amplitude norrealized relative to the DPPH should not be applied here. It is considered that the majority of Fe³⁺ ions behave antiferromagnetically and only a few are paramagnetic, but the latter do not behave antiferromagnetically at low temperature.更多还原