Unusual features of lattice dynamics in lawsonite near its phase transitions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F22%3A00557601" target="_blank" >RIV/68378271:_____/22:00557601 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0333381" target="_blank" >https://hdl.handle.net/11104/0333381</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s41598-022-09890-7" target="_blank" >10.1038/s41598-022-09890-7</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Unusual features of lattice dynamics in lawsonite near its phase transitions

Popis výsledku v původním jazyce

Lattice dynamics of a single crystal of lawsonite were studied over a broad range of frequencies (1 Hz to 20 THz) using impedance, THz time-domain and infrared spectroscopies. Based on polarized spectra of complex permittivity ε̂ measured as a function of temperature between 10 K and 500 K, we analyzed the properties of the two known phase transitions—an antiferrodistortive one near Tc1 = 270 K and a ferroelectric one, occurring at Tc2 = 124 K. At the pseudoproper ferroelectric phase transition, two independent anomalies in permittivity were observed. First, ε̂a exhibits a peak at Tc2 = 124 K due to critical slowing down of a relaxation in the GHz range. Second, infrared and THz spectra revealed an optical phonon softening towards Tc2 which causes a smaller but pronounced maximum in ε̂b. Such anomaly, consisting in a soft mode polarized perpendicularly to the ferroelectric axis, is unusual in ferroelectrics.

Název v anglickém jazyce

Unusual features of lattice dynamics in lawsonite near its phase transitions

Popis výsledku anglicky

Lattice dynamics of a single crystal of lawsonite were studied over a broad range of frequencies (1 Hz to 20 THz) using impedance, THz time-domain and infrared spectroscopies. Based on polarized spectra of complex permittivity ε̂ measured as a function of temperature between 10 K and 500 K, we analyzed the properties of the two known phase transitions—an antiferrodistortive one near Tc1 = 270 K and a ferroelectric one, occurring at Tc2 = 124 K. At the pseudoproper ferroelectric phase transition, two independent anomalies in permittivity were observed. First, ε̂a exhibits a peak at Tc2 = 124 K due to critical slowing down of a relaxation in the GHz range. Second, infrared and THz spectra revealed an optical phonon softening towards Tc2 which causes a smaller but pronounced maximum in ε̂b. Such anomaly, consisting in a soft mode polarized perpendicularly to the ferroelectric axis, is unusual in ferroelectrics.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/GA20-01527S" target="_blank" >GA20-01527S: Vzájemné interakce molekul vody lokalizovaných v krystalech směřující k jejich orientačnímu uspořádání</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Scientific Reports

ISSN

2045-2322

e-ISSN

2045-2322

Svazek periodika

12

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

6157

Kód UT WoS článku

000783752600072

EID výsledku v databázi Scopus

2-s2.0-85128204534