D. G. Schlom

Publications (2)5.09 Total impact

• Article: Infrared phonon spectroscopy of a compressively strained (001) SrTiO₃ film grown on a (110) NdGaO₃ substrate.

  D Nuzhnyy, J Petzelt, S Kamba, X Martí, T Cechal, C M Brooks, D G Schlom
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  ABSTRACT: Polarized infrared reflectivity was measured between 5 and 300 K on a 17 nm thick, 1.1% compressively strained epitaxial (001) SrTiO(3) film and the orthorhombic (110) NdGaO(3) substrate upon which it was grown. A strong in-plane infrared anisotropy of the NdGaO(3) substrate was observed and polar modes with B(1u)-and a mixture of B(2u) + B(3u)-symmetry were seen. At low temperatures three new modes arose in the 90-130 cm( - 1) range, which we assigned to 4f Nd electronic transitions. The in-plane SrTiO(3) film phonons showed strong stiffening compared to the phonon frequencies of bulk unstrained SrTiO(3), particularly the soft mode, and the in-plane phonon peaks were found to split. No anomalies were detected as a function of temperature in either the infrared response or lattice parameters of the compressively strained SrTiO(3) film, providing an absence of evidence for the out-of-plane ferroelectric phase transition predicted by theory.
  Journal of Physics Condensed Matter 02/2011; 23(4):045901. · 2.55 Impact Factor
• Article: Infrared phonon spectroscopy of a compressively strained (001) SrTiO3 film grown on a (110) NdGaO3 substrate

  D Nuzhnyy, J Petzelt, S Kamba, X Martí, T Čechal, C M Brooks, D G Schlom
  [show abstract] [hide abstract]
  ABSTRACT: Polarized infrared reflectivity was measured between 5 and 300 K on a 17 nm thick, 1.1% compressively strained epitaxial (001) SrTiO3 film and the orthorhombic (110) NdGaO3 substrate upon which it was grown. A strong in-plane infrared anisotropy of the NdGaO3 substrate was observed and polar modes with B1u-and a mixture of B2u + B3u-symmetry were seen. At low temperatures three new modes arose in the 90–130 cm − 1 range, which we assigned to 4f Nd electronic transitions. The in-plane SrTiO3 film phonons showed strong stiffening compared to the phonon frequencies of bulk unstrained SrTiO3, particularly the soft mode, and the in-plane phonon peaks were found to split. No anomalies were detected as a function of temperature in either the infrared response or lattice parameters of the compressively strained SrTiO3 film, providing an absence of evidence for the out-of-plane ferroelectric phase transition predicted by theory.
  Journal of Physics Condensed Matter 01/2011; 23(4):045901. · 2.55 Impact Factor