Ionic conductivity in gem-quality single-crystal alkali feldspar from the Eifel: temperature, orientation and composition dependence
Ionic conductivity in gem-quality single-crystal alkali feldspar from the Eifel: temperature, orientation and composition dependence
复制标题
DOI：
10.1007/s00269-015-0797-y
复制
发表时间：
2016-01
影响因子：
1.4
通讯作者：
H. El Maanaoui;F. Wilangowski;Aditya Maheshwari;H. Wiemhöfer;R. Abart;N. Stolwijk
中科院分区：
文献类型：
--
作者：
H. El Maanaoui;F. Wilangowski;Aditya Maheshwari;H. Wiemhöfer;R. Abart;N. Stolwijk
我们测量了来自Eifel/德国两个不同地点的单晶碱性长石的离子电导率，分别命名为Volkesfeld和Rockeskyller透长石，钾位点分数分别为0.83和0.71。 在300- 900 ℃温度范围内，由电化学阻抗谱得到的直流电导率显示出弱的成分依赖性，但单斜长石结构的b方向[]和-方向[]之间存在显著差异。从观察到的线性Arrhenius图得到的电导激活能在所有情况下都接近1.2 eV，这是非常相似的示踪剂在相同的晶体中的扩散的激活能。考虑到文献数据的K示踪剂扩散和扩散相关效应，目前的研究结果指出，在富钾碱性长石的碱亚晶格上的质量和电荷传输的空位机制的优势的magnitialcy机制。
We measured the ion conductivity of single-crystal alkali feldspar originating from two different locations in the Eifel/Germany, named Volkesfeld and Rockeskyller sanidine and having potassium site fractionsof 0.83 and 0.71, respectively. The dc conductivities resulting from electrochemical impedance spectroscopy over the temperature range of 300–900show a weak composition dependence but pronounced differences between theb-direction [] and-direction [] of the monoclinic feldspar structure. Conductivity activation energies obtained from the observed linear Arrhenius plots are close to 1.2 eV in all cases, which is closely similar to the activation energies of thetracer diffusivity in the same crystals. Taking into account literature data on K tracer diffusion and diffusion correlation effects, the present results point to a predominance of the interstitialcy mechanism over the vacancy mechanism in mass and charge transport on the alkali sublattice in potassium-rich alkali feldspar.