Dependence of Luminescence on Physical Structure in Zinc Borate Compounds

Luminescent zinc borate compounds have been prepared which can be obtained in either vitreous or crystalline form and which can be converted from one form to the other by purely physical processes. The dependence of luminescence of compounds of this type on physical structure has been investigated. It is found that changing a given compound from vitreous to granular state increases its luminescence many times. It is also found that zinc borate compounds can be made luminescent without the addition of an activator. The addition of an activator is found to result in a condensation of the emission bands and an increase in their wave-lengths. The bearing of these on the "solid solution" idea is discussed.