BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Chimie ParisTech - PSL - ECPv6.17.5//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-ORIGINAL-URL:https://www.chimieparistech.psl.eu
X-WR-CALDESC:Évènements pour Chimie ParisTech - PSL
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Paris
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20240331T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20241027T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20250330T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20251026T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20260329T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20261025T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Paris:20250306T140000
DTEND;TZID=Europe/Paris:20250306T163000
DTSTAMP:20250303T142027Z
CREATED:20250303T142027Z
LAST-MODIFIED:20250303T142027Z
UID:26790-1741269600-1741278600@www.chimieparistech.psl.eu
SUMMARY:Séminaire Programme Gradué Chimie PSL
DESCRIPTION:Ziman hydrodynamic regime in sapphire by Yo Machida\nGakushuin University\, Tokyo\n\nWhen an ideal insulator is cooled\, four regimes of thermal conductivity are expected to emerge one after another. Two of these\, the Ziman and the Poiseuille\, are hydrodynamic regimes in which collision among phonons are mostly Normal. It has been difficult to observe them\, save for a few insulators with high levels of isotopic and chemical purity. In my talk\, I will present the results of thermal transport measurements\, covering four decades of temperatures between 0.1 K and 900 K\, and show that sapphire displays all four regimes\, despite its isotopic impurity. In the Ziman regime\, the thermal conductivity exponentially increases reaching an amplitude as large as 35\,000 W/Km\, which is comparable with the maximum thermal conductivity attained by isotopically pure diamond and silicon. I will discuss the robust Ziman regime in sapphire is attributed to by the proximity of optical and acoustic phonon modes\, as a consequence of the large number of atoms in the primitive cell.\n \nZoom link: https://espci.zoom.us/j/85473746367?pwd=zlJpYsgdNcLeEjfM5iB0uphbxYaM1r.1  \nID: 854 7374 6367\nPasscode: Edwin_Hall
URL:https://www.chimieparistech.psl.eu/evenement-agenda/seminaire-programme-gradue-chimie-psl-135/
LOCATION:évènement hybride
END:VEVENT
END:VCALENDAR