A TIME-RESOLVED AL-27 NMR-STUDY OF THE COOLING PROCESS OF LIQUID ALUMINA FROM 2450-DEGREES-C TO CRYSTALLIZATION

被引：49

作者：

FLORIAN, P ^{[1
]}

MASSIOT, D ^{[1
]}

POE, B ^{[1
]}

FARNAN, I ^{[1
]}

COUTURES, JP ^{[1
]}

机构：

[1] CNRS,CRPHT,F-45071 ORLEANS 2,FRANCE

来源：

SOLID STATE NUCLEAR MAGNETIC RESONANCE | 1995年 / 5卷 / 03期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/0926-2040(95)01188-X

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Nuclear magnetic resonance is able to give insight into the structure and dynamics of liquids at very high temperature (T > 2000 degrees C). Al-27 NMR spectra have been recorded every 25 ms during the cooling of an aerodynamically levitated liquid alumina droplet from 2450 degrees C to crystallisation in less than 3 s. The temperature is measured jointly by pyrometry and NMR, and this time resolved experiment provides a unique way of exploring the temperature dependence of both the structure (shift) and the dynamics (relaxation time of Al-27 Of the liquid and the supercooled liquid alumina until the crystallisation of alpha-Al2O3. The apparent Arrhenian activation energy of 130 kJ mol(-1), derived from T-1 measurement, is understood as the signature of the macroscopic viscosity in this high temperature liquid.

引用

页码：233 / 238

页数：6

共 25 条

[1] DENSITIES OF SIO2-AL2O3 MELTS [J].