  Hexagonal boron nitride (h-BN) is an attractive van der Waals material for
studying fluorescent defects due to its large bandgap. In this work, we
demonstrate enhanced pink color due to neutron irradiation and perform electron
paramagnetic resonance (EPR) measurements. The new point defects are
tentatively assigned to doubly- occupied nitrogen vacancies with (S = 1) and a
zero-field splitting (D = 1.2 GHz). These defects are associated with a broad
visible optical absorption band and near infrared photoluminescence band
centered at ~ 490 nm and 820 nm, respectively. The EPR signal intensities are
strongly affected by thermal treatments in temperature range between 600 to
800{\deg}C, where also the irradiation - induced pink color is lost. Our
results are important for understanding of point defects in h-BN and their
deployment for quantum and integrated photonic applications.
