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Engineering Physics

Series

2003

Articles 1 - 3 of 3

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 …

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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 …

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Study Of A Growth Instability Of Γ-In[Sub 2]Se[Sub 3], C. Amory, J. C. Bernede, S. Marsillac Jan 2003

Study Of A Growth Instability Of Γ-In[Sub 2]Se[Sub 3], C. Amory, J. C. Bernede, S. Marsillac

Electrical & Computer Engineering Faculty Publications

γ-In[sub 2]Se[sub 3] thin film are deposited for various substrate temperatures in the range of 523–673 K. This study shows that at 573 and 673 K the thin films are well crystallized with grains aligned along the c axis. Between these temperatures, a domain of instability appears where the γ-In[sub 2]Se[sub 3] thin films have a randomly orientation and the c-lattice parameter increases. The presence of the metastable phase κ-In[sub 2]Se[sub 3], during the growth, can explain the existence of this domain of instability. The insertion of Zn during the preparation process allows us to stabilize the phase κ at …

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