Enhanced magnetoresistivity of modulation-doped manganite superlattices
ORAL
Abstract
Modulation-doped epitaxial superlattices of La$_{1-x}$Ca$_{x}$MnO$_{3}$ and La$_{1-y}$Ca$_{y}$MnO$_{3}$ layers alternating with x=1/3 and y=1/2 on (001) LaAlO$_{3}$ substrates have been grown by magnetron sputtering. The magnetoresistivity (MR) has been greatly enhanced over a wide temperature range in comparison with the parent compounds. The MR is -50{\%} at 0. 5 Tesla and -90{\%} at 4 Tesla. At low temperatures, a quantum interference effect (QIE) was observed, as manifested by a resistivity minimum considered to be incurred by the 3D e-e interactions. The modulation-doping approach is an enabling strategy to boost the sensitivity of colossal magnetoresistive oxides in response to an applied magnetic field.
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