论文标题
电池材料Lifeepo中的反塞特障碍$ _4 $
Antisite disorder in the battery material LiFePO$_4$
论文作者
论文摘要
我们报告了详细的磁力测定法和高频电子自旋共振（HF-ESR）测量值，这些测量可以详细研究单一晶体延伸的LifePo $ _4 $，即Fe $^{2+} $} $ - 和li $ $^+$ $ - ions中的life antisite障碍。数据表明，在li-positions处的fe $^{2+} $离子的磁矩不会参与LifePo $ _4 $中的远程反铁磁序，而是形成不准时的时刻。在抗铁矿缺损处的磁矩的各向异性轴附着在主晶体学方向上。通过HF-ESR研究检测到的相关线性共振分支证实了这些矩的局部特征。磁各向异性以$δ= 220（3）$ 〜GHz，$δ\ sim50 $ 〜GHz和高度各向异性$ g $ -Factor，即$ G_ \ Mathrm {a} = 1.4 $，$ G_ \ g_ \ mathrm {$ g_ \ mathrm {$ g_ {b， 6.3 $。我们展示了一种从磁性研究中精确确定LifePo $ _4 $中的Fe-抗铁疾病的一般方法，这意味着li-positions li-positions in 0.53 \％\％的顺磁性fe $^{2+} $ ions的密度。
We report detailed magnetometry and high-frequency electron spin resonance (HF-ESR) measurements which allow detailed investigation on Li-Fe antisite disorder in single-crystalline LiFePO$_4$, i.e., exchange of Fe$^{2+}$- and Li$^+$-ions. The data imply that magnetic moments of Fe$^{2+}$-ions at Li-positions do not participate in long-range antiferromagnetic order in LiFePO$_4$ but form quasi-free moments. Anisotropy axes of the magnetic moments at antisite defects are attached to the main crystallographic directions. The local character of these moments is confirmed by associated linear resonance branches detected by HF-ESR studies. Magnetic anisotropy shows up in significant zero-field splittings of $Δ= 220(3)$~GHz, $Δ'\sim50$~GHz and a highly anisotropic $g$-factor, i.e., $g_\mathrm{a} = 1.4$, $g_\mathrm{b} = 2.0$, and $g_\mathrm{c} = 6.3$. We demonstrate a general method to precisely determine Fe-antisite disorder in LiFePO$_4$ from magnetic studies which implies a density of paramagnetic Fe$^{2+}$-ions at Li-positions of 0.53\%.
