Department of Physics, University of Michigan, Ann Arbor, MI 48109-1040;
Department of Physics, University of Michigan, Ann Arbor, MI 48109-1040.
Proc Natl Acad Sci U S A. 2019 Jun 25;116(26):12638-12641. doi: 10.1073/pnas.1901245116. Epub 2019 Jun 10.
The inverted resistance method was used in this study to extend the bulk resistivity of [Formula: see text] to a regime where the surface conduction overwhelms the bulk. Remarkably, regardless of the large off-stoichiometric growth conditions (inducing disorder by samarium vacancies, boron interstitials, etc.), the bulk resistivity shows an intrinsic thermally activated behavior that changes ∼7-10 orders of magnitude, suggesting that [Formula: see text] is an ideal insulator that is immune to disorder.
在这项研究中,采用了反向电阻法将[Formula: see text]的体电阻率扩展到表面传导超过体传导的区域。值得注意的是,无论采用何种大的非化学计量比生长条件(通过钐空位、硼间隙等诱导无序),体电阻率都表现出固有热激活行为,变化约 7-10 个数量级,这表明[Formula: see text]是一种理想的绝缘体,不受无序的影响。