Principles and Applications of Ferroelectrics and Related Materials

Lines, M. E.; Glass, A. M.

doi:10.1093/acprof:oso/9780198507789.001.0001

Cited by 2,927 publications

(3,464 citation statements)

References 0 publications

Supporting

126

Mentioning

3,298

Contrasting

Unclassified

Order By: Relevance

“…, using the same notation as in (1). Equation (3) gives the relation between temperature and degree of inversion once the enthalpy coefficients α and β are determined.…”

Section: Thermodynamic Modelmentioning

confidence: 99%

“…1 The simplest of these compounds is lead metaniobate, PbNb 2 O 6 or PN, which has a high Curie temperature of 570 • C. 2 It is, however, only stable at temperatures above 1200-1250 • C, and metastable with respect to a rhombohedral polymorph below this temperature range. [3][4][5] A lead-free analogue to PN is strontium barium niobate, Sr x Ba 1-x Nb 2 O 6 or SBN, which is apparently stable in the TTB structure down to ambient temperature, although with a lower T C of 70-200 • C, depending on composition.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the energetics of cation ordering in tungsten-bronze-type oxides

Olsen

Selbach

Grande

2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Oxides with the tetragonal tungsten bronze (TTB) structure are well-known ferroelectrics that show a large flexibility both with respect to chemical composition and cation ordering. Two of the simplest compounds in this family are lead metaniobate (PbNb 2 O 6 or PN) and strontium barium niobate (Sr x Ba 1-x Nb 2 O 6 or SBN). While PN is a classical ferroelectric, SBN goes from ferroelectric to relaxor-like with increasing Sr content, with a polar direction different from that in PN. The partially occupied sublattices in both systems give the possibility for cation order-disorder phenomena, but it is not known if or how this influences the polarization and ferroelectricity. Here, we use density functional theory (DFT) calculations to investigate how cation and cation vacancy ordering influences the energetics of these compounds, by comparing both the energy differences and the barriers for transition between different cation configurations. We extend the thermodynamic model of O'Neill and Navrotsky, originally developed for cation interchange in spinels, to describe the order-disorder phenomenology in TTB oxides. The influence of order-disorder processes on the functional properties of PN and SBN is discussed.

show abstract

“…, using the same notation as in (1). Equation (3) gives the relation between temperature and degree of inversion once the enthalpy coefficients α and β are determined.…”

Section: Thermodynamic Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the energetics of cation ordering in tungsten-bronze-type oxides

Olsen

Selbach

Grande

2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…KTO has an insulting band gap of 3.75 eV and does not show the ferroelectric phase transition that is common for perovskites. 16,17 The band gap of STO amounts to 3.2 eV. Its electronic, transport, ferroelectric, catalytic, and dielectric properties have been widely studied.…”

mentioning

confidence: 99%

Charge transfer mechanism for the formation of metallic states at the KTaO3/SrTiO3interface

2011

View full text Add to dashboard Cite

The electronic and optical properties of the KTaO 3 /SrTiO 3 heterointerface are analyzed by the full-potential linearized augmented plane-wave approach of density functional theory. Optimization of the atomic positions points at subordinate changes in the crystal structure and chemical bonding near the interface, which is due to a minimal lattice mismatch. The creation of metallic interface states thus is not affected by structural relaxation but can be explained by charge transfer between transition metal and oxygen atoms. It is to be expected that a charge transfer is likewise important for related interfaces such as LaAlO 3 /SrTiO 3 . The KTaO 3 /SrTiO 3 system is ideal for disentangling the complex behavior of metallic interface states, since almost no structural relaxation takes place. During the past decade, heterointerfaces based on perovskite transition metal oxides have attracted a great deal of attention due to the discovery of remarkable electronic and magnetic properties. They are of special importance for device applications, such as field effect transistors, bipolar transistors, and light emitting diodes. 1,2 Ohtomo and Hwang 3 have reported on metallicity at the interface between LaAlO 3 and SrTiO 3 , two insulators with sizable band gaps of 5.6 and 3.2 eV, respectively. The creation of metallic states is intimately connected to the structural relaxation. 4 The high mobility of the charge carriers at this interface has initiated many investigations, 5,6 as did the discovery of superconductivity at low temperature. 7 However, despite huge experimental and theoretical efforts, many aspects of the physical picture of the LaAlO 3 /SrTiO 3 (LAO/STO) interface remain open. [8][9][10][11][12][13] To a large extent, this appears to be the result of a complex interplay between structural and electronic reconstructions as well as defects. 14 An essential ingredient of the electronic reconstruction is the transfer of charge between different orbitals, i.e., alterations of the orbital occupations, which can modify the electronic properties of transition metal oxides significantly. 15 An interesting system to disentangle the effects of the charge transfer from other parameters is the KTaO 3 /SrTiO 3 (KTO/STO) heterointerface. KTO has an insulting band gap of 3.75 eV and does not show the ferroelectric phase transition that is common for perovskites. 16,17 The band gap of STO amounts to 3.2 eV. Its electronic, transport, ferroelectric, catalytic, and dielectric properties have been widely studied. [18][19][20][21] Interestingly, the lattice match of KTO with STO is much better than that of LAO with STO. As a consequence, KTO is a promising material for application as an insulator in STO-based field-effect devices. Recently, Kalabukhov et al. 22 have investigated the KTO/STO interface experimentally and found close relations to the LAO/STO interface, even though at the (KO) − (TiO 2 ) 0 contact 0.5 holes per unit cell are transferred, while at the (LaO) + (TiO2) 0 contact 0.5 electrons are transferred.The elect...

show abstract

“…Over the last several decades, a formula of perovskites, ABO 3 has attracted broad interest due to their piezoelectricity, ferroelectricity, colossal magneto resistivity, and photoluminescence [1][2][3][4]. Perovskite and ilmenite oxides which are the structure of ABO 3 , represent a prominent of advanced compounds involved in many areas of science and technology [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of new phosphor based MTiO3

DAYAN

2015

Journal of Nuclear Sciences

View full text Add to dashboard Cite

Jo u r nal h o m e p age: h t t p : / / j n s . a n k a r a . e d u . t r /DOI ABSTRACTIn this study, new titanate phosphors were synthesized. The Dy 3+ , Eu 3+ , Ho 3+ rare-earth ions were used as dopants to CaTiO 3 , SrTiO 3 , and BaTiO 3 host crystals. The optimization of reaction conditions were carried out by thermogravimetry (TG) and differential thermal analysis (DTA) methods. The mixtures to achieve a solid state reaction were heated in porcelain crucibles for preheating process at 600 o C and 800 o C and final heating process at 1000 o C for 16 hours in the open atmosphere. The reaction products were characterized by X-ray powder diffractions (XRD). Surface investigations and elemental analysis were determined by using SEM-EDX instrument. Photoluminescence spectrophotometer (PL) was used for the observation of the excitation and emission spectra.

show abstract

Principles and Applications of Ferroelectrics and Related Materials

Cited by 2,927 publications

References 0 publications

On the energetics of cation ordering in tungsten-bronze-type oxides

On the energetics of cation ordering in tungsten-bronze-type oxides

Charge transfer mechanism for the formation of metallic states at the KTaO3/SrTiO3interface

Synthesis and characterization of new phosphor based MTiO3

Contact Info

Product

Resources

About