Stony meteorite thermal properties and their relationship with meteorite chemical and physical states
Stony meteorite thermal properties and their relationship with meteorite chemical and physical states
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DOI：
10.1111/j.1945-5100.2012.01331.x
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发表时间：
2012-03
影响因子：
2.2
通讯作者：
SJ C.P.OPEIL;SJ G.J.CONSOLMAGNO;D. Safarik;D. T. Britt
中科院分区：
文献类型：
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作者：
SJ C.P.OPEIL;SJ G.J.CONSOLMAGNO;D. Safarik;D. T. Britt
摘要-在我们正在进行的陨石物理性质调查中，我们迄今已经测量了17块石质陨石在5-300K温度范围内的热导率。这里，我们报道了9块普通球粒陨石、1块顽辉石球粒陨石和玄武岩非球粒陨石法兰克福和洛杉矶(雪戈特)的新结果。我们发现，热导率明显低于通过平均其组成矿物的实验室电导率而预期的，与温度的依赖关系与纯矿物的预期电导率不同。此外，我们还发现，无论陨石的成分或类型如何，测量的样品的孔隙率的倒数与它们的导热系数之间都存在线性关系。我们的结论是，热导率是由陨石中激波诱导的微裂缝的存在控制的，这些微裂缝为热能通过声子的传输提供了障碍。与电导率不同的是，我们首次测量的热容是温度的函数(在洛杉矶)，它表明热容主要是氧化物组成的函数，而不是样品的物理状态的强烈影响。
Abstract– In our ongoing survey of meteorite physical properties, we have to date measured the thermal conductivity for seventeen stony meteorites at temperatures ranging from 5 K to 300 K. Here, we report new results for nine ordinary chondrites, one enstatite chondrite, and the basaltic achondrites Frankfort (howardite) and Los Angeles (shergottite). We find that thermal conductivity is significantly lower than would be expected from averaging the laboratory conductivities of their constituent minerals, with a dependence on temperature different from the expected conductivity of pure minerals. In addition, we find a linear relationship between the inverse of the porosity of the samples measured and their thermal conductivity, regardless of meteorite composition or type. We conclude that thermal conductivity is controlled by the presence of shock‐induced microcracks within the meteorites, which provide a barrier to the transmission of thermal energy via phonons. In contrast to conductivity, our first measurement of heat capacity as a function of temperature (on Los Angeles) suggests that heat capacity is primarily a function of oxide composition and is not strongly affected by the physical state of the sample.