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In situ energy dispersive x-ray diffraction for natural marmatite (Zn0.76Fe0.23S) is performed up to 17. 7 GPa and 623 K. It is fit, ted by the Birch-Murnaghan equation of state (EOS) that Ko and α0 for marmatite are 85(3)GPa and 0.79(16)*10^-4 K^-1, respectively. Fe^2+ isomorphic replacing to Zn^2+ in natural crystal is responsible for high bulk modulus and thermal expansivity of marmatite. Temperature derivative of bulk modulus (OK/OT)p for marmatite is fitted to be -0.044(23) GPaK^-1. The unambiguous B3-B1 phase boundaries for marmatite are determined to be Pupper(GPa)= 15.50 - 0.016T(℃) and Plower (GPa)=9.94-0.012T(℃) at 300-623K. 相似文献
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利用金刚石压腔同步辐射X射线就位衍射技术,在室温、最高压力达13 GPa条件下,对采自云南个旧锡矿的天然锡石做了X衍射测量。结果表明,在实验压力范围内锡石未发生相变,其晶胞参数随压力增大而逐渐减小。与前人合成锡石实验结果相比,本次实验测定的晶胞参数偏大。由Birch状态方程对实验结果p-V进行最小二乘法拟合,得出锡石的KT(0)=228 GPa。分析认为,在天然矿物晶体中,Zr对Sn的类质同象置换是晶胞参数偏大的主要原因。 相似文献
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Ultrasonic P wave velocity(VP) and quality factor(Qp value,on behalf of attenuation)in pyroxenite were presented as unctions of pressures (0.3-3.0GPa) and temperatures (20-1170℃) .The experimental results show that Vp and Qp depend upon pressure and temperature,Vp and Qp in pyroxenite increase more rapidly at the pressure 0.3-1.4GPa than those at 1.4-3.0Gpa.As the temperature rising from 20℃to about 1170℃ at the pressure 3.0GPa.an almost linear decrease up to 11% in Vp was observed,and Qp drops from 243 at room temperature to 68at 1170℃ with decreasing 72%,The experimental data indicate that the pressure and temperature induced fabric changes and frictional sliding and dislocation in pyroxenite play a key role in wave propagation in rocks. 相似文献
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Evidence for Grain Boundary Transport from Impedance Spectroscopy of Gabbro at 1-2GPa up to 890℃
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Impedance spectra of gabbro were measured at 1-2 GPa and up to 890℃ with applied frequency of 12 to 10^5 Hz. At temperatures below 680℃, only one impedance arc corresponding to the grain interior conduction process occurs. Owing to the grain boundary transport with increasing temperature, the impurities occur at the grain boundaries, resulting in the second arc corresponding to the grain boundary conduction process over the frequency range of 12 to 10^3Hz above 680℃, and the resistivities of the grain interior and the grain boundary conduction mechanisms add in series. The total conductivity of this rock is dominated by the grain interior conductivity and the impurities have no significant effect on the total electrical conductivities. 相似文献
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高温高压下黑云斜长片麻岩的电性研究 总被引:4,自引:0,他引:4
在压力1 GPa、温度250~1 100 ℃、频率0.1 Hz~1 MHz的条件下,采用阻抗谱方法,对来自阴山造山带的太古代黑云斜长片麻岩进行了电导率实验研究。实验发现:(1) 所有样品的阻抗谱都是由一个大的高频半圆弧Ⅰ和一个小的被压缩了的低频弧Ⅱ组成,阻抗弧Ⅰ主要代表矿物颗粒内部传导机制,阻抗弧Ⅱ更有可能代表的是样品和电极之间的传导机制;(2) 电导率随温度的变化遵循Arrhenian定律,但在700~750 ℃间有近一个量级的跳跃,通过对比实验前后样品的显微照片和探针分析数据,认为这一电导率的大幅跳跃可能是样品中黑云母发生大量脱水熔融的缘故;(3) 在高温段750~1 100 ℃,部分熔融样品的电导率主要由钠离子传导控制;(4) 在低温段250~700 ℃,样品的激活能为0.53 eV;在高温段750~1 100 ℃,样品的激活能为1.41 eV。激活能的改变可能与样品的结构变化有关,还与样品和熔体中钠的含量以及扩散有关。 相似文献
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利用已有的α和β石英压缩性、热膨胀性、弹性及相变温度压力资料,计算了α-β石英相转变时,α和β石英的晶胞参数。依据虎克定律以及高压下β石英的弹性参数,估算了α-β石英相转变时的应变、应力和应变能。结果表明,在0~1.1 GPa条件下,随压力升高,α-β石英相变的线应变介于-0.006~0.005之间,体应变介于-0.016~0.012之间,应力介于-0.46~0.14 GPa之间;应变能介于965~2 760 kJ/m3之间。压力为0.5 GPa左右时,α-β石英相变的应变、应力和应变能均达到最小值。在此基础上,讨论了壳内大规模酸性岩浆活动引起的α-β石英相变对壳内岩石的作用。 相似文献
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