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Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University of Hong Kong

Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

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Page 1: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Workshop on Amorphous Solids, Hong Kong,

September 2008

Lecture 1: Introduction to glasses

Itamar Procaccia

Institute of Theoretical Physics

Chinese University of Hong Kong

Page 2: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Glasses: disordered materials that lack the periodicity of crystals but behave mechanically

like solids.

•Created by cooling a liquid “fast enough” to avoid crystallization. (Known for millennia).

•The glassy state is ubiquitous in nature. (Obsidian, window glass, fiber optics, plastics, metallic glasses and alloys, etc. etc.)

•Our aim is to understand the molecular processes by which liquids acquire amorphous rigidity.

•We will try to understand simple models in great detail.

Page 3: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Typical phase diagram:

Some experimentalexamples

Page 4: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

The TTT-diagram

Page 5: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University
Page 6: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Slowing down

The stretched exponential approximation:

The Vogel-Fulcher fit

Page 7: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University
Page 8: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Experimental methodsBroad Band Dielectric Spectroscopy (BDS)

Page 9: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

A nice riddle:

Page 10: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Specific heat spectroscopy

Page 11: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

The energy landscape picture

Page 12: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University
Page 13: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University

Mechanical Properties

Monte Carlo:

Page 14: Workshop on Amorphous Solids, Hong Kong, September 2008 Lecture 1: Introduction to glasses Itamar Procaccia Institute of Theoretical Physics Chinese University