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Title: Effects of Pressure and Electric Field on the Relaxational Dielectric Properties of K0.97Li0.03O3(KLT-3).


Abstract not provided.

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Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: Proposed for presentation at the American Physical Society held March 13-17, 2006 in Baltimore, MD.
Country of Publication:
United States

Citation Formats

Samara, George A, Grubbs, Robert K., Venturini, Eugene Leo, and Boatner, L.A. Effects of Pressure and Electric Field on the Relaxational Dielectric Properties of K0.97Li0.03O3(KLT-3).. United States: N. p., 2006. Web.
Samara, George A, Grubbs, Robert K., Venturini, Eugene Leo, & Boatner, L.A. Effects of Pressure and Electric Field on the Relaxational Dielectric Properties of K0.97Li0.03O3(KLT-3).. United States.
Samara, George A, Grubbs, Robert K., Venturini, Eugene Leo, and Boatner, L.A. Sun . "Effects of Pressure and Electric Field on the Relaxational Dielectric Properties of K0.97Li0.03O3(KLT-3).". United States. doi:.
title = {Effects of Pressure and Electric Field on the Relaxational Dielectric Properties of K0.97Li0.03O3(KLT-3).},
author = {Samara, George A and Grubbs, Robert K. and Venturini, Eugene Leo and Boatner, L.A.},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}

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  • Relaxor behavior and lattice dynamics have been studied by employing dielectric measurements and neutron-scattering methods for a single crystal of K{sub 1-x}Li{sub x}TaO{sub 3} (x=0.05), where a small amount of a Ca impurity ({approx}15 ppm) was incorporated during the single-crystal growth procedure. The dielectric constant {epsilon}({omega},T) shows qualitatively similar behavior to that of Ca-free KLT with x=0.043 with both compositions exhibiting relaxational properties with no evidence for a ferroelectric transition. The absolute value of {epsilon}({omega},T=0) for the present crystal is larger by an order of magnitude than that of the Ca-free sample due to charge carriers induced by the Camore » doping. This large value is shown to be due to a Maxwell-Wagner relaxation process associated with the low temperature (<8 K) activation of frozen electronic carriers. The dielectric loss tangent tan {delta} reveals three Debye-type relaxations with Arrhenius activation energies of 80, 135, and 240 meV that are assigned to Li{sup +} dipoles, Ca{sup 2+}-related relaxation, and the Li{sup +}-Li{sup +} dipolar pairs, respectively. In the neutron scattering results, diffuse scattering ridges appear around the nuclear Bragg peaks along the [100] direction below {approx}150 K and phonon line broadening features start to appear at even higher temperatures suggesting that polar nanoregions (PNRs) start to form at these temperatures. These results are supported by the dielectric data that reveal relaxor behavior starting at {approx}200 K on cooling. From analyses of the diffuse intensities at different zones, we have derived atomic displacements in the PNRs. The results suggest that the displacements include a uniform phase shift of all of the atoms in addition to the atomic displacements corresponding to a polarization vector of the transverse-optic soft-ferroelectric-mode, a finding that is analogous to that in the prototypical relaxor material Pb(Mg{sub 13}Nb{sub 23})O{sub 3}.« less
  • Monte-Carlo simulations have recently been used to construct the susceptibility diagram of multipactor discharge on a dielectric, under the assumption that the RF electric field is parallel to the dielectric surface. This diagram, constructed from kinematic considerations, turns out to be extremely useful in the prediction of the saturation level. Here, the authors generalize the susceptibility diagram in two aspects: inclusion of an external magnetic field and the effects of an oblique RF electric field. It is found that the presence of an external magnetic field does not qualitatively change the susceptibility diagram, regardless of the orientation of the magneticmore » field. This statement holds for all magnetic fields simulated, up to those values whose cyclotron frequency is on the order of the RF frequency. The effects of an oblique RF electric field show a more significant change on the susceptibility diagram. In general, the lower bound (in RF electric field) of the susceptibility diagram does not suffer a qualitative change as {phi} increases from zero, where {phi} is the angle between the RF electric field and the dielectric surface. However, the upper bound changes markedly once {phi} exceeds about 10 degrees. The overall effect is that nonzero {phi} narrows the range of RF electric field in which multipactor can occur. However, since the saturation of multipactor is determined from the lower boundary of the susceptibility diagram, the present study then shows that oblique RF electric field and external magnetic field do not qualitatively affect the existence or the saturation level. More important, then, is the effect of outgassing that is considered elsewhere in this Conference.« less
  • Ferroelectric (FE) films, especially PZT films, have received increasing attention for microelectronics applications such as FE memory and in high density DRAM`S. While rare earth doped PbTiO{sub 3} ceramics have been studied for SAW and piezoelectric applications, rare earth doped films seldom have been systematically explored. A series of sol-gel derived PbTiO{sub 3} films with varying amounts (5--15 mole %) of rare earths (such as, Nd, Sm, Tb, Dy, Er Yb and La) have been prepared using acetates and alkoxides as precursors. The solutions were spin coated onto platinized Si wafers. The effects of the type and amount of raremore » incorporation on the phase assembly and microstructure have been quantified. The results of dielectric characterization (e.g., dielectric constant, dissipation factor and leakage currents) and FE behaviors (viz.remanent polarization, and coercive field) are presented these films exhibited low leakage currents (3E-10 A/cm{sup 2}) and much higher dielectric constant (up to 525) compared to undoped PbTiO{sub 3} films.« less
  • The effect of a post deposition anneal on the structure and dielectric properties of epitaxial Sr{sub 1{minus}x}Ba{sub x}TiO{sub 3} (SBT) thin films with x = 0.35, 0.50 and 0.60 has been measured. The films were grown by pulsed laser deposition on LaAlO{sub 3} (001) substrates at 750 C in 350 mTorr of oxygen. The as-deposited films were single phase, (00{ell}) oriented with {omega}-scan widths for the (002) reflection between 0.16{degree} and 0.50{degree}. The dielectric properties of the as-deposited films exhibit a broad temperature dependence and a peak which is as much as 50 K below the peak in bulk SBT.more » Also, the lattice parameter, as measured by x-ray diffraction, of the as-deposited films was larger than the bulk indicating strain in the films. The as-deposited films were annealed for 8 hours at 900 C in oxygen. The dielectric properties of the annealed films were closer to that of bulk SBT and the lattice parameter was closer to the bulk lattice parameter indicating a reduction of strain. Annealing of as-deposited films also resulted in an increased dielectric tuning without increased dielectric loss.« less
  • Highlights: • Mn{sub 3}TeO{sub 6} and Co{sub 3}TeO{sub 6} are antiferromagnets with corundum related structures. • The structural and magnetic properties of Mn{sub 3−x}Co{sub x}TeO{sub 6} ceramics were investigated. • All compounds adopt the trigonal structure of Mn{sub 3}TeO{sub 6} up to at least x = 2.4. • The antiferromagnetic transition temperature monotonously increases with x. • NPD data evidences the magnetic structure of the Mn{sub 3−x}Co{sub x}TeO{sub 6} ceramics. - Abstract: The effects of Co{sup 2+} doping on the structural, magnetic and dielectric properties of the multiferroic frustrated antiferromagnet Mn{sub 3}TeO{sub 6} have been investigated. Ceramic samples of themore » solid solution series Mn{sub 3−x}Co{sub x}TeO{sub 6} were prepared by a solid-state reaction route. X-ray and neutron powder diffraction and electron microscopy techniques were combined with calorimetric, dielectric and magnetic measurements to investigate the dependence of the crystal structure and physical properties on temperature and composition. It is shown that the compounds with x ≤ 2.4 adopt the trigonal corundum-related structure of pure Mn{sub 3}TeO{sub 6} (space group R3{sup ¯}) in the temperature range 5–295 K and that the lattice parameters a and c and the unit-cell volume V decrease linearly with increasing Co{sup 2+} concentration. The low-temperature magnetic susceptibility and heat capacity data evidence the antiferromagnetic ordering of all samples. The Neel temperature linearly increases with Co{sup 2+} concentration x. Curie–Weiss fits of the high temperature susceptibility indicate that the magnetic frustration decreases with x. The derived magnetic structure of Mn{sub 3}TeO{sub 6} can be described as an incommensurately modulated magnetic spin state with k = [0, 0, k{sub z}] and an elliptical spin-spiral order of spins within the chains of MnO{sub 6} octahedra. With increasing Co{sup 2+} concentration the propagation vector k{sub z} changes from 0.453 (x = 0) to 0.516 (x = 2.4). The magnetic anisotropy changes as well, leading to a reorientation of the spiral-basal plane. A possible coexistence of long-range order of electrical dipoles and magnetic moments in Mn{sub 3−x}Co{sub x}TeO{sub 6} is discussed.« less