Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Engineering Physics

University of Nebraska - Lincoln

Series

2003

Articles 1 - 2 of 2

Full-Text Articles in Physics

Ferroelectric-Field-Induced Tuning Of Magnetism In The Colossal Magnetoresistive Oxide La1Àxsrxmno3, X. Hong, A. Posadas, A. Lin, C. H. Ahn Jan 2003

Ferroelectric-Field-Induced Tuning Of Magnetism In The Colossal Magnetoresistive Oxide La1Àxsrxmno3, X. Hong, A. Posadas, A. Lin, C. H. Ahn

Xia Hong Publications

A ferroelectric field effect approach is presented for modulating magnetism in the colossal magnetoresistive oxide La1-xSrxMnO3 (LSMO). The ferromagnetic Curie temperature of ultrathin LSMO films was shifted by 35 K reversibly using the polarization field of the ferroelectric oxide Pb(ZrxTi1-x)O3 in a field effect structure. This shift was also observed in magnetoresistance measurements, with the maximum magnetoresistance ratio at 6 T increasing from 64% to 77%. This model system approach does not introduce substitutional disorder or structural distortion, demonstrating that regulating the carrier concentration alone changes the magnetic phase transition …


Ferroelectricity In Free Niobium Clusters, Ramiro Moro, Xiaoshan Xu, Shuangye Yin, Walt A. De Heer Jan 2003

Ferroelectricity In Free Niobium Clusters, Ramiro Moro, Xiaoshan Xu, Shuangye Yin, Walt A. De Heer

Xiaoshan Xu Papers

Electric deflections of gas-phase, cryogenically cooled, neutral niobium clusters [NbN; number of atoms (N) = 2 to 150, temperature (T) = 20 to 300 kelvin], measured in molecular beams, show that cold clusters may attain an anomalous component with very large electric dipole moments. In contrast, room-temperature measurements show normal metallic polarizabilities. Characteristic energies kBTG(N) [Boltzmann constant kB times a transition temperature TG(N)] are identified, below which the ferroelectric-like state develops. Generally, TG decreases [110 > TG(N) > 10K] as …