If we review the literature, most of articles are based on crystalline materials. However we find less amount of literature on applications of amorphous metal oxide materials. Definitely, in solar cells, glasses etc we use amorphous materials but still it is not so popular like crystalline materials. Can somebody enlighten me why amorphous metals and metals oxides are not so popular?
Shashikant Shinde
This is a relatively simple question to research on Google. In tonnage terms the biggest amorphous materials manufactured in the nano region are fumed silica and carbon black. Both used as rheology modifiers (silica in toothpaste, for example, and carbon black in car tires). Water could be considered an amorphous material but I'm sure that this isn't what you intended in your question.
In the pharmaceutical industry then amorphous materials will have higher (desired) solubility. The problem is if they're metastable and convert to a (less effective) crystalline form.
Typically crystalline materials are easier to characterize (e.g. by XRD) and metal oxides tend to be highly crystalline. It's hard to make many of them in an amorphous form - rather like metals. They can be made by shock freezing of metallic melts but this isn't often convenient.
Take a look at this paper: 'Research Advances of Amorphous Metal Oxides in Electrochemical Energy Storage and Conversion' Article Research Advances of Amorphous Metal Oxides in Electrochemic...
Amorphous materials are generally disordered structure systems. It do not have long range structural periodicity. Also, they have poor electrical conductivity due to very low carrier concentration and simple electronic structure with a wide band gap, as can be seen in the nanostructure oxide materials or other systems. The best possible application of such kinds of materials or to be used as a bad conductor because they do not allow the heat propagation as phonon scattering is very dominant. Provided the bad thermal conduction, it is very good to use them as a thermal insulator. If you can optimise the carrier concentration in such kind of system with maintaining the low thermal conductivity it can open a wide range of applications such as making devices in the electronic industry. Please have look at the conducting transparent glass materials. These materials are the nowadays hot topic of research in the field of thermoelectric. People are trying to find suitable materials with optimised carrier concentration and disordered structure, it is very challenging to reduce the electrical resistivity, but some materials which have local impurity states within the energy band called coherent states provide the way to conduct electricity sufficiently.
People are using amorphous non-stoichiometric Ti-oxide films for bolometer applications.
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