It is argued that the structure of real glasses, especially the multi-component ones, can be investigated at low temperatures by exploiting the existence of tunneling systems (TSs) in the glass which can be described by a suitable extension of the standard tunneling model (STM) as was proposed by one of us. Even the simplest glass - as already argued in 1921 and in 1937 by A.A. Lebedev - is likely to contain elementary crystallites (not yet crystals) embedded in a random network, and our work has shown that this statement is even more true in the case of phase-separating, multi-component glasses, solids containing network-modifying components in their chemical make-up. Using the concept of TSs specifically nesting within the crystallites, we describe how our extended TM can explain puzzling experiments in glasses at low temperatures and in the presence of a magnetic field for a variety of amorphous insulators. The success of the theoretical analysis of a large number of experimental data confirms the crystallite hypothesis, clarifies the nature of the TS and opens the way to a possible new form of spectroscopy for the amorphous solid state in which the TSs play the role the atomic nuclei play in NMR spectroscopy. © 2013 Elsevier B.V.

The glassy state - Magnetically viewed from the frozen end

2014

Abstract

It is argued that the structure of real glasses, especially the multi-component ones, can be investigated at low temperatures by exploiting the existence of tunneling systems (TSs) in the glass which can be described by a suitable extension of the standard tunneling model (STM) as was proposed by one of us. Even the simplest glass - as already argued in 1921 and in 1937 by A.A. Lebedev - is likely to contain elementary crystallites (not yet crystals) embedded in a random network, and our work has shown that this statement is even more true in the case of phase-separating, multi-component glasses, solids containing network-modifying components in their chemical make-up. Using the concept of TSs specifically nesting within the crystallites, we describe how our extended TM can explain puzzling experiments in glasses at low temperatures and in the presence of a magnetic field for a variety of amorphous insulators. The success of the theoretical analysis of a large number of experimental data confirms the crystallite hypothesis, clarifies the nature of the TS and opens the way to a possible new form of spectroscopy for the amorphous solid state in which the TSs play the role the atomic nuclei play in NMR spectroscopy. © 2013 Elsevier B.V.
2014
Istituto per i Processi Chimico-Fisici - IPCF
Crystalline-like ordering in glasses
Low temperature physics
Magnetic effects in non-magnetic glasses
Oxide and organic glasses (non-metallic)
Tunneling systems in glasses
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/259134
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