Application of Mössbauer Effect on the Crystallization of Several Glasses

Abstract

The structural change of glass from a non-crystalline State to a poly- crystalline State caused by controlled crystallization is a very important and interesting phenomenon both from the scientific and industrial point of view. Crystallized glasses are extensively utilized in many industrial fields such as mechanical, electrical, and nuclear engineering because of their ultra low thermal expansion and high mechanical strength [1,2]. Crystallization of glasses is generally known to proceed by two steps, nucleation and crystal growth. The crystallized glasses are known to consist of many crystalline particles mixed into the remaining glass phase. Because of this, crystallized glasses are still regarded as non-crystalline, and are called glass-ceramics [1,2]. As for the crystallization of glasses, several techniques [3–8] have so far been utilized to study glass ceramics. Differential thermal analysis [4–6] and differential scanning calorimetry [7] are known to be very useful. Mossbauer studies on the crystallization of glasses [9–11] have also been performed, and the method proved to be extremely useful for the structural study of borate [12–15], borosilicate [16,17], phosphate [18,19], borophosphate [20], germanate [21,22], zinc Chloride [23], and zirconium tetrafluoride [24] glasses. Structural studies of glasses by Mossbauer spectroscopy and NMR have been reviewed by Muller-Warmuth and Eckert [25].