论文标题
FCC-朗萨姆中温度依赖空位浓度的Arrhenius定律的分解
Breakdown of the Arrhenius Law of the Temperature Dependent Vacancy Concentration in fcc-Lanthanum
论文作者
论文摘要
我们使用原位正电子歼灭光谱测量了与温度相关的空缺浓度，以确定基本FCC-LA中空置形成的焓$ h_ \ text {f} $和熵$ s_ \ text {f text {f} $。然而，适用于数据分析的Arrhenius定律未能解释$ s_ \ text {f} $和$ h_ \ text {f} $：特别是$ s_ \ s_ \ text {f} = 17（f} = 17（2）〜k_ \ text {b} $与其他元素相比，$ y infortial nivex $ y nive $ h.发现在理论上偏离了三个以上的标准偏差，$ h_ \ text {f} = 1.46〜 \ text {ev} $（我们的\ acs {dft}计算la at $ t = 0〜 \ text {k} {k} $）。根据$ s_ \ text {f}^\ prime = -0.0120（14）〜k_ \ k_ \ text {b}/\ text {b}/\ text {k} $ carcects the anharmonic潜在的潜在，从$ s_ \ prime = -0.0120（14）〜k_ \ prime = -0.0120（14）〜核算Anharmonic潜力引入空缺。
We measured the temperature dependent equilibrium vacancy concentration using in-situ positron annihilation spectroscopy in order to determine the enthalpy $H_\text{f}$ and entropy $S_\text{f}$ of vacancy formation in elementary fcc-La. The Arrhenius law applied for the data analysis, however, is shown to fail in explaining the unexpected high values for both $S_\text{f}$ and $H_\text{f}$: in particular $S_\text{f}=17(2)~k_\text{B}$ is one order of magnitude larger compared to other elemental metals, and the experimental value of $H_\text{f}$ is found to be more than three standard deviations off the theoretical one $H_\text{f}=1.46~\text{eV}$ (our \acs{dft} calculation for La at $T=0~\text{K}$). A consistent explanation is given beyond the classical Arrhenius approach in terms of a temperature dependence of the vacancy formation entropy with $S_\text{f}^\prime=-0.0120(14)~k_\text{B}/\text{K}$ accounting for the anharmonic potential introduced by vacancies.
