Effect of neutron irradiation on the low-temperature specific heat and thermal conductivity of magnesium oxide

The specific heat and thermal conductivity of neutron-irradiated MgO have been measured to 0.1 K. There is no evidence for the existence of the localized excitations found in glassy materials or found in neutron-irradiated crystalline SiO₂. This result is consistent with the suggestion that polymorphism is conducive to the formation of an amorphous phase and to the existence of the localized excitations.