Doping dependence of the anomalous Hall effect in La 1 − x Sr x Co O 3
2006; American Physical Society; Volume: 73; Issue: 17 Linguagem: Inglês
10.1103/physrevb.73.174421
ISSN1550-235X
Autores Tópico(s)Physics of Superconductivity and Magnetism
ResumoThe anomalous Hall effect has been studied for single crystals of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}\mathrm{Co}{\mathrm{O}}_{3}$ $(0.17\ensuremath{\leqslant}x\ensuremath{\leqslant}0.30)$. The Hall conductivity for $x=0.3$ is proportional to the magnetization, which is consistent with the Kaplus-Luttinger theory. At the lowest temperature, it shows the highest reported value among transition-metal oxides $(165\phantom{\rule{0.3em}{0ex}}{\ensuremath{\Omega}}^{\ensuremath{-}1}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1})$. For the lower doping crystals, by contrast, the Hall conductivity shows a downturn with decreasing temperature, being distinct from the temperature dependence of the magnetization. In particular, the Hall conductivity for $x=0.17$ shows a sign change around $50\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The negative component of the Hall resistivity seems to be related to the glassy nature of the magnetism in this doping region.
Referência(s)