6533b873fe1ef96bd12d4b2a

RESEARCH PRODUCT

Charge-carrier density collapse in and epitaxial thin films

Gerhard JakobF. MartinW. WesterburgJ.a.a.j. PerenboomP.j.m. Van Bentum

subject

Materials scienceCondensed matter physicsTransition temperatureAtmospheric temperature rangeCondensed Matter PhysicsMagnetic hysteresisElectronic Optical and Magnetic MaterialsCondensed Matter::Materials ScienceMagnetizationFerromagnetismElectrical resistivity and conductivityHall effectCondensed Matter::Strongly Correlated ElectronsCharge carrier

description

We measured the temperature dependence of the linear high field pH of La0.67Ca0.33MnO3 Tc = 232K) and La0.67Sr0.33MnO3 Tc = 345K) thin films in the temperature range from 4 K up to 360 K in magnetic fields up to 20 T. At low temperatures we find a charge-carrier density of 1.3 and 1.4 holes per unit cell for the Ca- and Sr-doped compound, respectively. In this temperature range electron-magnon scattering contributes to the longitudinal resistivity. At the ferromagnetic transition temperature Tc a dramatic drop in the number of charge-carriers n down to 0.6 holes per unit cell, accompanied by an increase in unit cell volume, is observed. Corrections of the Hall data due to a non saturated magnetic state will lead a more pronounced charge-carrier density collapse.

https://doi.org/10.1007/s100510051059