Author
Malcolm E. Lines
Other affiliations: AT&T Corporation
Bio: Malcolm E. Lines is an academic researcher from Bell Labs. The author has contributed to research in topics: Raman spectroscopy & Raman scattering. The author has an hindex of 8, co-authored 15 publications receiving 5272 citations. Previous affiliations of Malcolm E. Lines include AT&T Corporation.
Papers
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06 Oct 1977
TL;DR: In this paper, the theory of ferroelectricity in terms of soft modes and lattice dynamics is developed and modern techniques of measurement, including X-ray, optic, and neutron scattering, infra-red absorption, and magnetic resonance.
Abstract: The book develops the modern theory of ferroelectricity in terms of soft modes and lattice dynamics and also describes modern techniques of measurement, including X-ray, optic, and neutron scattering, infra-red absorption, and magnetic resonance. It includes a discussion of the related phenomena of antiferroelectricity, pyroelectricity, and ferroelasticity and seconds on domains, thin films, ceramics, and polymers, leading on to a comprehensive survey of potential and actual device capabilities for pyroelectric detection, memories, display, and modulation. It should provide an authoritative account for those engaged in research or graduate ferroelectric or pyroelectric devices.
4,931 citations
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TL;DR: In this paper, the variation of peak intensities with composition were investigated in several systems and the observed variations were found to be consistent with calculations based on a theoretical approach developed by Lines and coworkers.
Abstract: Exceptionally high Raman intensities have been observed in glasses containing major amounts of Tl 2 O, PbO, Bi 2 O 3 , and / or Sb 2 O 3 in combination with GeO 2 , SiO 2 , and / or As 2 O 3 . Raman peaks were more than 30× the strength of vitreous SiO 2 and 3× vitreous germania (based on spectra reduced to absolute zero and corrected for refractive index differences). The variation of peak intensities with composition were investigated in several systems and the observed variations were found to be consistent with calculations based on a theoretical approach developed by Lines and coworkers. Two compositions show particular promise for active fiber device applications: one based on Sb 2 O 3 ·GeO 2 , exhibiting a strong bridged anion mode with a frequency shift near 400 cm −1 , and one based on Bi 2 O 3 ·PbO·GeO 2 ·SiO 2 , with a superposition of strong acoustic Raman heavy metal modes with a frequency shift near 140 cm −1 .
120 citations
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TL;DR: In this paper, the authors showed that the calcium aluminate (CA) family of glasses should exhibit intrinsic optical losses at 1.55 μm, markedly lower than the 0.16 dB/km of SiO2, is confirmed by scattering measurements.
Abstract: The suggestion made in an earlier paper, that the calcium aluminate (CA) family of glasses should exhibit intrinsic optical losses at 1.55 μm, markedly lower than the 0.16 dB/km of SiO2, is confirmed by scattering measurements. The total (i.e. Rayleigh, Brillouin and Raman) scattering losses are found to be ≈ 0.04 dB/km at 1.55 μm with a projected minimum total attenuation for pure silica-free samples of as low as 0.015 dB/km at ≈1.9 μm. Measurements are also made of multiphonon edge absorption in the 4–6 μm regime and a preliminary assessment given of the materials outlook for the preparation of ultralow-loss CA-glass fibers.
101 citations
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TL;DR: In this paper, the theoretical expressions for absolute Raman intensities derived in part I have been generalized in two ways; one for application to multicomponcnt glasses and the other to enable qualitative global predictions to be made in terms of such fundamentals as valency, bond length and mass.
Abstract: The theoretical expressions for absolute Raman intensities derived in part I have been generalized in two ways; one for application to multicomponcnt glasses and the other to enable qualitative global predictions to be made in terms of such fundamentals as valency, bond length and mass. From the latter it is anticipated that the most intense Raman spectra among good glass formers will most likely be found in multicomponent heavy-metal oxide glasses. Using the full multicomponent theory, a detailed comparison is then made with experimental Raman spectra for ten different binary through quaternary germanate glasses containing Tl 2 O, PbO, Bi 2 O 3 and/or Sb 2 O 3 . Adopting a simple model which is based on the assumption of a dominantly four-fold coordinated germanium site leads to estimates for the number of bridged-anion and non-bridged-anion modes which, when coupled with the theoretical intensity expressions for such components, explains in a surprisingly quantitative manner the measured intensities of the corresponding Raman spectral features. An equally detailed discussion is presented of the lowest frequency acoustic-Raman or ‘boson’ peak and absolute intensity predictions again compare well with experiment for all ten germanate compositions.
95 citations
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TL;DR: In this paper, three rather general types of lattice vibrational modes were recognized as potentially able to produce major Raman features in glasses and calculated their contributions to absolute integrated Raman scattering loss (in dB/km).
Abstract: An ability to predict absolute Raman intensities of the major spectral features in glasses in general is becoming increasingly important in association with the search for new optic fiber materials since the phenomenon of stimulated Raman scattering is an important mechanism in assessing the capabilities and limitations of such fibers in many applications. In this paper we recognize three rather general types of lattice vibrational mode which are potentially able to produce major Raman features in glasses and calculate their contributions to absolute integrated Raman scattering loss (in dB/km). A comparison with experiment is given for vitreous SiO2, GeO2, B2O3, BeF2 and P2O5. The extension to multicomponent glasses and full predictive capabilities of the derived formulae in a general context are discussed in the accompanying paper (part II).
42 citations
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TL;DR: A ferroelectric crystal exhibits a stable and switchable electrical polarization that is manifested in the form of cooperative atomic displacements that arises through the quantum mechanical phenomenon of exchange.
Abstract: A ferroelectric crystal exhibits a stable and switchable electrical polarization that is manifested in the form of cooperative atomic displacements. A ferromagnetic crystal exhibits a stable and switchable magnetization that arises through the quantum mechanical phenomenon of exchange. There are very few 'multiferroic' materials that exhibit both of these properties, but the 'magnetoelectric' coupling of magnetic and electrical properties is a more general and widespread phenomenon. Although work in this area can be traced back to pioneering research in the 1950s and 1960s, there has been a recent resurgence of interest driven by long-term technological aspirations.
6,813 citations
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TL;DR: It is found that even a weak magnetoelectric interaction can lead to spectacular cross-coupling effects when it induces electric polarization in a magnetically ordered state.
Abstract: Magnetism and ferroelectricity are essential to many forms of current technology, and the quest for multiferroic materials, where these two phenomena are intimately coupled, is of great technological and fundamental importance. Ferroelectricity and magnetism tend to be mutually exclusive and interact weakly with each other when they coexist. The exciting new development is the discovery that even a weak magnetoelectric interaction can lead to spectacular cross-coupling effects when it induces electric polarization in a magnetically ordered state. Such magnetic ferroelectricity, showing an unprecedented sensitivity to ap plied magnetic fields, occurs in 'frustrated magnets' with competing interactions between spins and complex magnetic orders. We summarize key experimental findings and the current theoretical understanding of these phenomena, which have great potential for tuneable multifunctional devices.
3,683 citations
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TL;DR: In this paper, the authors report results of electronic-structure calculations on two classic examples of ferroelectric perovskites, BaTiO3 and PbTiO2, and demonstrate that hybridization between the titanium 3d states and the oxygen 2p states is essential for ferroelectivity.
Abstract: FERROELECTRIC materials are characterized by a switchable macroscopic polarization. Most technologically important ferroelectrics are oxides with a perovskite structure. The origin of their ferroelectric behaviour is unclear, however, and there is incomplete understanding of why similar, but chemically different, perovskites should display very different ferroelectric behaviour. The great sensitivity of ferroelectrics to chemistry, defects, electrical boundary conditions and pressure arises from a delicate balance between long-range Coulomb forces (which favour the ferroelectric state) and short-range repulsions (which favour the nonpolar cubic structure). To model the transition accurately, total-energy techniques are required which incorporate the effects of charge distortion and covalency. Here I report results of electronic-structure calculations on two classic examples of ferroelectric perovskites, BaTiO3 and PbTiO3, and demonstrate that hybridization between the titanium 3d states and the oxygen 2p states is essential for ferroelectricity. The different ferroelectric phase behaviour of the two materials is also clear: in PbTiO3, the lead and oxygen states hybridize, leading to a large strain that stabilizes the tetragonal phase, whereas in BaTiO3 the interaction between barium and oxygen is completely ionic, favouring a rhombohedral structure.
2,417 citations
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TL;DR: In this article, the authors introduce the current state of development in the application of ferroelectric thin films for electronic devices and discuss the physics relevant for the performance and failure of these devices.
Abstract: This review covers important advances in recent years in the physics of thin-film ferroelectric oxides, the strongest emphasis being on those aspects particular to ferroelectrics in thin-film form. The authors introduce the current state of development in the application of ferroelectric thin films for electronic devices and discuss the physics relevant for the performance and failure of these devices. Following this the review covers the enormous progress that has been made in the first-principles computational approach to understanding ferroelectrics. The authors then discuss in detail the important role that strain plays in determining the properties of epitaxial thin ferroelectric films. Finally, this review ends with a look at the emerging possibilities for nanoscale ferroelectrics, with particular emphasis on ferroelectrics in nonconventional nanoscale geometries.
1,908 citations
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TL;DR: Ferroelectric, dielectric, and piezoelectric properties of ferroelectric thin films and ceramics are reviewed with the aim of providing an insight into different processes which may affect the behaviour of Ferroelectric devices.
Abstract: Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics are reviewed with the aim of providing an insight into different processes which may affect the behaviour of ferroelectric devices, such as ferroelectric memories and micro-electro-mechanical systems. Taking into consideration recent advances in this field, topics such as polarization switching, polarization fatigue, effects of defects, depletion layers, and depolarization fields on hysteresis loop behaviour, and contributions of domain-wall displacement to dielectric and piezoelectric properties are discussed. An introduction into dielectric, pyroelectric, piezoelectric and elastic properties of ferroelectric materials, symmetry considerations, coupling of electro-mechanical and thermal properties, and definitions of relevant ferroelectric phenomena are provided.
1,835 citations