TY  - JOUR
AU  - Tenne, D.A.
AU  - Farrar, A.K.
AU  - Brooks, C.M.
AU  - Heeg, T.
AU  - Schubert, J.
AU  - Jang, H.W.
AU  - Bark, C.W.
AU  - Folkman, C.M.
AU  - Eom, C.B.
AU  - Schlom, D.G.
TI  - Ferroelectricity in nonstoichiometric SrTiO3 films studied by ultraviolet Raman spectroscopy
JO  - Applied physics letters
VL  - 97
SN  - 0003-6951
CY  - Melville, NY
PB  - American Institute of Physics
M1  - PreJuSER-12005
SP  - 142901
PY  - 2010
N1  - This work was supported in part by the NSF through Grant Nos. DMR-0705127 (D.A.T.), DMR-0507146 (D.G.S.), ECCS-0708759 (C.B.E.), and DMR-0906443 (C.B.E.) and through the MRSEC program by Grant No. DMR-0820404 (C.M.B), DOE EPSCoR Grant No. DE-FG02-04ER46142 (D.A.T.), and Research Corporation for Science Advancement Grant No. 7134 (D.A.T.).
AB  - Homoepitaxial Sr1+xTiO3+delta films with -0.2 <= x <= 0.25 grown by reactive molecular-beam epitaxy on SrTiO3 (001) substrates have been studied by ultraviolet Raman spectroscopy. Nonstoichiometry for strontium-deficient compositions leads to the appearance of strong first-order Raman scattering at low temperatures, which decreases with increasing temperature and disappears at about 350 K. This indicates the appearance of a spontaneous polarization with a paraelectric-to-ferroelectric transition temperature above room temperature. Strontium-rich samples also show a strong first-order Raman signal, but the peaks are significantly broader and exhibit a less pronounced temperature dependence, indicating a stronger contribution of the disorder-activated mechanism in Raman scattering. (C) 2010 American Institute of Physics. [doi:10.1063/1.3499273]
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000282765700051
DO  - DOI:10.1063/1.3499273
UR  - https://juser.fz-juelich.de/record/12005
ER  -