Glass transition of ultrathin films probed by X-ray reflectivity

被引：4

作者：

Cecchetto, E ^{[1
]}

de Souza, NR ^{[1
]}

Jérôme, B ^{[1
]}

机构：

[1] Univ Amsterdam, Dept Chem Engn, NL-1018 WW Amsterdam, Netherlands

来源：

JOURNAL DE PHYSIQUE IV | 2000年 / 10卷 / P7期

关键词：

D O I：

10.1051/jp4:2000749

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

X-ray reflectometry was used to measure the temperature dependence of the thickness of ultrathin films of two low-molecular-weight glass formers. In bulk samples, this type of measurements reveals the presence of a glass transition by a sudden break of slope. We have observed a broadening of the glass transition in films thinner than roughly 150 nm, indicating an inhomogeneous distribution of relaxation times in these films. Our results are explained by confinement effect and interpreted in the frame of a theoretical model based on the concept of collective dynamics over a cooperative length.

引用

页码：247 / 250

页数：4

共 12 条

[1] Length scale of cooperativity in the dynamic glass transition [J].

Arndt, M ;

Stannarius, R ;

Groothues, H ;

Hempel, E ;

Kremer, F .

PHYSICAL REVIEW LETTERS, 1997, 79 (11) :2077-2080

[2] A method to determine the kinetics of a supercooled liquid by temperature scanning measurements applied to (Li,Na)acetate and GeO2 [J].

Brüning, R ;

Crowell, T .

JOURNAL OF NON-CRYSTALLINE SOLIDS, 1999, 248 (2-3) :183-193

[3]

DEWIT PP, 1996, Patent No. 3476

[4] Comments on the mode coupling theory for structural relaxation [J].

Gotze, W ;

Sjogren, L .

CHEMICAL PHYSICS, 1996, 212 (01) :47-59

[5]

JACKSON CL, 1991, J NONCRYST SOLIDS, V221, P131

[6] Dynamics of glass-forming materials confined in thin films [J].

Jérôme, B .

JOURNAL OF PHYSICS-CONDENSED MATTER, 1999, 11 (10A) :A189-A197

[7] SIZE-DEPENDENT DEPRESSION OF THE GLASS-TRANSITION TEMPERATURE IN POLYMER-FILMS [J].

KEDDIE, JL ;

JONES, RAL ;

CORY, RA .

EUROPHYSICS LETTERS, 1994, 27 (01) :59-64

[8] INTERFACE AND SURFACE EFFECTS ON THE GLASS-TRANSITION TEMPERATURE IN THIN POLYMER-FILMS [J].

KEDDIE, JL ;

JONES, RAL ;

CORY, RA .

FARADAY DISCUSSIONS, 1994, 98 :219-230

[9] OBSERVATION OF TEMPERATURE-DEPENDENT THICKNESSES IN ULTRATHIN POLYSTYRENE FILMS ON SILICON [J].

ORTS, WJ ;

VANZANTEN, JH ;

WU, WL ;

SATIJA, SK .

PHYSICAL REVIEW LETTERS, 1993, 71 (06) :867-870

[10] Effect of strongly favorable substrate interactions on the thermal properties of ultrathin polymer films [J].

vanZanten, JH ;

Wallace, WE ;

Wu, WL .

PHYSICAL REVIEW E, 1996, 53 (03) :R2053-R2056

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