Luminescence spectrum from hexagonal YMnO3

Luminescence spectrum and its temperature dependence have been investigated for hexagonal YMnO3 crystal which is ferroelectric below TC=914 K and becomes simultaneously antiferromagnetic below TN=74 K. The luminescence spectrum is as broad as two-magnon Raman scattering spectrum. The luminescence intensity is comparable to the latter at room temperature and it increases rapidly as the temperature decreases. These characteristics are discussed based upon other optical responses and theoretical results.