01306nas a2200325 4500008004100000020001400041245006500055210006500120260001600185300001400201490000700215520044400222653001900666653001600685653001900701653001200720653002300732653001400755100001500769700001500784700001300799700001200812700001100824700001300835700001700848700001200865700001400877700001700891856007200908 2003 eng d a1386-947700aDirect measurements of optical phonons in SrTiO3 nanosystems0 aDirect measurements of optical phonons in SrTiO3 nanosystems c2003/07/01/ a236 - 2390 v193 a
We use terahertz time domain spectroscopy to examine finite size effects on the optical phonon modes in SrTiO3 thin films. In temperature-dependent measurements we find a near absence of mode softening in the TO1 phonon frequency. Furthermore we see an increase in the soft mode frequency with reduced thickness. Both of these results correlate well with the reduced dielectric response observed for nanoscale ferroelectric systems.
10aFerroelectrics10aFinite size10aMode softening10aphonons10aStrontium titanate10aTerahertz1 aWolpert, D1 aKorolev, K1 aSachs, S1 aKnab, J1 aCox, W1 aCerne, J1 aMarkelz, A.G1 aZhao, T1 aRamesh, R1 aMoeckly, B.H uhttps://www.sciencedirect.com/science/article/pii/S1386947703003059