Počet záznamů: 1

Soft-mode behavior and incipient ferroelectricity in Na.sub.1/2./sub.Bi.sub.1/2./sub.Cu.sub.3./sub.Ti.sub.4./sub.O.sub.12./sub..

SYSNO ASEP	0347911
Druh ASEP	J - Článek v odborném periodiku
Zařazení RIV	J - Článek v odborném periodiku
Poddruh J	Článek ve WOS
Název	Soft-mode behavior and incipient ferroelectricity in Na_1/2Bi_1/2Cu₃Ti₄O₁₂.
Tvůrce(i)	Ferrarelli, M.C. (GB) Nuzhnyy, Dmitry (FZU-D)_{RID, ORCID} Sinclair, D.C. (GB) Kamba, Stanislav (FZU-D)_{RID, ORCID, SAI}
Zdroj.dok.	Physical Review. B - ISSN 1098-0121 Roč. 81, č. 22 (2010), 224112/1-224112/7
Poč.str.	6 s.
Jazyk dok.	eng - angličtina
Země vyd.	US - Spojené státy americké
Klíč. slova	infrared and terahertz spectroscopy ; soft mode ; incipient ferroelectrics
Vědní obor RIV	BM - Fyzika pevných látek a magnetismus
CEP	GA202/09/0682 GA ČR - Grantová agentura ČR
CEZ	AV0Z10100520 - FZU-D (2005-2011)
UT WOS	000279090100001
DOI	10.1103/PhysRevB.81.224112
Anotace	Na_1/2Bi_1/2Cu₃Ti₄O₁₂.(NBCTO) ceramics exhibit high intrinsic relative permittivity of ~145 at 300 K that rises on cooling and levels off below ~50 K with a value of ~260 at 10 K without any signature of a structural transition. Such behavior is a typical feature of incipient ferroelectrics such as the perovskite CaTiO3. Infrared and terahertz spectroscopy on NBCTO ceramics are presented and reveal a room-temperature soft polar optic mode at ~34 cm-1 that softens on cooling and is responsible for the temperature dependence of the relative permittivity. The temperature dependence of the soft-mode frequency obeys the Barrett formula with the onset of quantum fluctuations T1 occurring near 85 K and a hypothetical Curie temperature T0 of ~−155 K. A fitted vibrational zero-point energy (kBT1)/2 is in good agreement with the measured soft-mode frequency.
Pracoviště	Fyzikální ústav
Kontakt	Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579
Rok sběru	2011

Počet záznamů: 1