Skelný a Verweyův přechod v magnetitu v detailu

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F07%3A00004424" target="_blank" >RIV/00216208:11320/07:00004424 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/07:00099771

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Glass-like and Verwey transitions in magnetite in details

Popis výsledku v původním jazyce

We have measured low field DC and low frequency AC magnetic properties of single crystals of magnetite with continuously reading high-resolution SQUID magnetometer in temperature range from 5 to 150 K. The measurements show hysteresis of Verwey transition in temperature and linear opening of energy gap of about 40 meV above the transition. Below the transition an AC response may be well explained by a thermally activated charge hopping. For frequencies of the driving AC field close to the hopping frequency a spin glasslike behavior is observed. Extracted values of the energy gap, activation energy and attempt period agree with those found from infrared complex conductivity measurements. Characteristic temperature of the glass-like transition coincideswith minimum of the spinspin relaxation time observed by NMR with this sample. Both NMR and our data may be explained consistently on the basis of the fluctuation-dissipation theorem.

Název v anglickém jazyce

Glass-like and Verwey transitions in magnetite in details

Popis výsledku anglicky

We have measured low field DC and low frequency AC magnetic properties of single crystals of magnetite with continuously reading high-resolution SQUID magnetometer in temperature range from 5 to 150 K. The measurements show hysteresis of Verwey transition in temperature and linear opening of energy gap of about 40 meV above the transition. Below the transition an AC response may be well explained by a thermally activated charge hopping. For frequencies of the driving AC field close to the hopping frequency a spin glasslike behavior is observed. Extracted values of the energy gap, activation energy and attempt period agree with those found from infrared complex conductivity measurements. Characteristic temperature of the glass-like transition coincideswith minimum of the spinspin relaxation time observed by NMR with this sample. Both NMR and our data may be explained consistently on the basis of the fluctuation-dissipation theorem.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

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Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2007

Kód důvěrnosti údajů

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

Název periodika

Journal of Magnetism and Magnetic Materials

ISSN

0304-8853

e-ISSN

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Svazek periodika

310

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

1

Strana od-do

"E203"-"E205"

Kód UT WoS článku

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EID výsledku v databázi Scopus

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