Dielectric properties and dynamical conductivity of LaTiO3: From dc to optical frequencies

Abstract

We provide a complete and detailed characterization of the temperature-dependent response to ac electrical fields of LaTiO3, a Mott-Hubbard insulator close to the metal-insulator transition. We present combined dc, broadband dielectric, mm-wave, and infrared spectra of ac conductivity and dielectric constant, covering an overall frequency range of 17 decades. The dc and dielectric measurements reveal information on the semiconducting charge-transport properties of LaTiO3, indicating the importance of Anderson localization, and on the dielectric response due to ionic polarization. In the infrared region, the temperature dependence of the phonon modes gives strong hints for a structural phase transition at the magnetic ordering temperature. In addition, a gap-like electronic excitation following the phonon region is analyzed in detail. We compare the results to the soft-edge behavior of the optical spectra characteristic for Mott-Hubbard insulators. Overall a consistent picture of the charge-transport mechanisms in LaTiO3 emerges.

arXiv comment11 pages, 8 figures, 1 table

References in corpus (11)

• Materials with Colossal Dielectric Constant: Do They Exist?
• Orbital liquid in three dimensional Mott insulator: $LaTi{O}_3$
• Crystal and magnetic structure of LaTiO3 : evidence for non-degenerate $t_{2g}$-orbitals
• Spin Dynamics and Orbital State in LaTiO_3
• The response of disordered matter to electromagnetic fields
• Theory of Electronic Ferroelectricity
• Order from disorder: Quantum spin gap in magnon spectra of LaTiO_3
• Evidence for Jahn-Teller distortions at the antiferromagnetic transition in LaTiO${}_3$
• Calculation of photoemission spectra of the doped Mott insulator La_{1-x}Sr_xTiO_3 using LDA+DMFT(QMC)
• Determination of the parameters of semiconducting CdF2:In with Schottky barriers from radio-frequency measurements
• Electrodynamics of a Coulomb Glass in n-type Silicon

Cited by in corpus (18)

• Colossal dielectric constants in transition-metal oxides
• Colossal dielectric constants in single-crystalline and ceramic CaCu3Ti4O12 investigated by broadband dielectric spectroscopy
• Correlated Electron Materials and Field Effect Transistors for Logic: A Review
• A variational pseudo-self-interaction correction approach: ab-initio description of correlated oxides and molecules
• Atomic scale electronic structure of the ferromagnetic semiconductor Cr2Ge2Te6
• Broadband dielectric response of CaCu3Ti4O12: From dc to the electronic transition regime
• Apparent giant dielectric constants, dielectric relaxation, and ac-conductivity of hexagonal perovskites La1.2Sr2.7BO7.33 (B = Ru, Ir)
• The magnetic structure of the Jahn-Teller System LaTiO3
• Correlated vs. conventional insulating behavior in the Jeff=1/2 vs. 3/2 bands in the layered iridate Ba2IrO4
• Phase separation in doped Mott insulators
• Spin-orbital excitation continuum and anomalous electron-phonon interaction in the Mott insulator LaTiO${}_3$
• Dielectric anomaly at the orbital order-disorder transition in LaMnO_(3+delta)
• IR-active optical phonons in Pnma-1, Pnma-2 and R3c phases of LaMnO_{3+δ}
• Effect of pressure on the polarized infrared optical response of quasi-one-dimensional LaTiO${}_{3.41}$
• Collective Charge Excitations below the Metal-to-Insulator Transition in BaVS3
• The spin-wave spectrum of the Jahn-Teller system LaTiO3
• Anisotropy of the paramagnetic susceptibility in LaTiO${}_3$: The electron-distribution picture in the ground state
• Dynamic conductivity of semiconducting manganites approaching the metal-insulator transition