Zobrazeno 1 - 10
of 22
pro vyhledávání: '"P. da R. Andrade"'
Publikováno v:
Ferroelectrics. 8:637-643
The behavior of the low frequency dielectric constants of NaNO2 as a function of frequency and temperature is explained by assuming a correct balance between the Lyddane-Sachs-Teller and Mason-Debye relaxation contributions to the dielectric constant
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::c559ce5f3a041f597a0f40fae0b7fdfc
https://doi.org/10.1080/00150197408234181
https://doi.org/10.1080/00150197408234181
Publikováno v:
physica status solidi (b). 67:129-136
Numerical evaluations for the effect of a Brownian sublattice on polariton dispersion were made. Using reasonable physical values for the coupling between long optical phonons and polaritons with a dielectric disorder mechanism a set of theoretical i
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ca0dd56171d222e3475809442f8a2f81
https://doi.org/10.1002/pssb.2220670111
https://doi.org/10.1002/pssb.2220670111
Publikováno v:
physica status solidi (b). 61:K71-K75
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3f672d0fc60a382c4e918ed97d3547fc
https://doi.org/10.1002/pssb.2220610254
https://doi.org/10.1002/pssb.2220610254
Publikováno v:
physica status solidi (b). 70:635-639
Recently a model theory was given by the authors for the coupling of long optical phonons and polaritons with a Debye-Mason relaxation in order-disorder crystals. This theory is extended to the case of applying an external electric field to the cryst
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::b91467c779bfb4f43333ea357db5c4c5
https://doi.org/10.1002/pssb.2220700224
https://doi.org/10.1002/pssb.2220700224
Publikováno v:
Physical Review B. 13:4907-4917
The room-temperature Raman spectra of LiTa${\mathrm{O}}_{3}$ for all symmetry phonons are investigated. We make a new assignment of the phonons, which agrees with the selection rules of a ${C}_{3}$ symmetry instead of ${C}_{3v}$, contrary to Kaminow
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::eab73e6902163b6932943651488eb5f2
https://doi.org/10.1103/physrevb.13.4907
https://doi.org/10.1103/physrevb.13.4907
Publikováno v:
Journal of Thermal Analysis. 9:93-99
K4Fe(CN)6·3H2O was studied by a derivatograph in the temperature range +20° to +300° and dielectric constant (e) measured from −80° to +150°. The loss of the three water molecules occurs at 105° and thee vs T curve shows a Debye relaxation be
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::94c731fdd23da22f3400f7eb4effe4d7
https://doi.org/10.1007/bf01909270
https://doi.org/10.1007/bf01909270
Publikováno v:
Physical Review B. 9:1077-1084
The dielectric constant of sodium chlorate has been analyzed on the basis of a Mason-Debye-type relaxation formula. A consistent description of the temperature dependence of the phonon structure and the dielectric-constant behavior as a function of f
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::aa367e20f9ec43eaa9a9bd8eeb5f826e
https://doi.org/10.1103/physrevb.9.1077
https://doi.org/10.1103/physrevb.9.1077
Autor:
P. da R. Andrade, L. Merten
Publikováno v:
physica status solidi (b). 62:641-653
A set of coupled equations describing the effect of a disorder mechanism on polariton dispersion is given. The treatment differs from that one finds in the literature because the disorder mechanism is not taken as a second-order perturbation. A parti
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f0e99c95ce7becb14bef454879664941
https://doi.org/10.1002/pssb.2220620234
https://doi.org/10.1002/pssb.2220620234
Publikováno v:
physica status solidi (b). 70:641-651
In a preceding paper a set of coupled equations describing the effect of a disorder mechanism on the dispersion of optical phonons and polaritons was given. These equations are valid for the paraelectric region of ferroelectric crystals. The set of c
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e6dade5d89e68571bb30b7fa5db67839
https://doi.org/10.1002/pssb.2220700225
https://doi.org/10.1002/pssb.2220700225
Autor:
S. P. S. Porto, P. da R. Andrade
Publikováno v:
Solid State Communications. 14:547-550
A simple theoretical derivation is given to show that one may expect a hard core for the phonon frequency at the transition temperature. This approach implies that the frequency of the phonon will follow ω ∝ {[1 + γ(T − T C )] V 0 } 1 2 instead
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::60d00c108b21889a6f94f809e885b887
https://doi.org/10.1016/0038-1098(74)91008-4
https://doi.org/10.1016/0038-1098(74)91008-4