Polaronic nature of a muonium-related paramagnetic center in SrTiO3
Polaronic nature of a muonium-related paramagnetic center in SrTiO3
复制标题
SrTiO3 中与 μ 相关的顺磁中心的极化性质
DOI：
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发表时间：
2019
影响因子：
4
通讯作者：
K. Shimomura
中科院分区：
文献类型：
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作者：
T. Ito;W. Higemoto;A. Koda;K. Shimomura
用Muon自旋旋转谱研究了钛酸锶钙钛矿中与Mu有关的顺磁中心的超精细特征和热稳定性。顺磁中心的超精细耦合张量具有显著的偶极特征，表明电子自旋密度主要分布在钛原子上，形成一个小的极化子，靠近离化的Mu^+$施主。基于氢-Mu的类比，在稀薄掺杂极限下，间隙氢也有望形成这样的极化子中心。发现Mu~+-极化子络合物的热解离激活能为30(3)meV，这表明扭曲晶格所需的应变能与电子局域化所获得的电子能相当。
The hyperfine features and thermal stability of a muonium (Mu)-related paramagnetic center were investigated in the SrTiO$_3$ perovskite titanate via muon spin rotation spectroscopy. The hyperfine coupling tensor of the paramagnetic center was found to have prominent dipolar characteristics, indicating that the electron spin density is dominantly distributed on a Ti site to form a small polaron near an ionized Mu$^+$ donor. Based on a hydrogen-Mu analogy, interstitial hydrogen is also expected to form such a polaronic center in the dilute doping limit. The small activation energy of 30(3) meV found for the thermal dissociation of the Mu$^+$-polaron complex suggests that the strain energy required to distort the lattice is comparable to the electronic energy gained by localizing the electron.