Spin-carrying defects possessing optically addressable ground states in semiconductors allow the development of solid-state quantum technologies. Recently such type of defect has been found in hexagonal boron nitride (hBN) and identified as a negatively charged boron vacancy (VB-). Here we investigate the possibility to create VB- centers in hBN by irradiation with high-energy protons (EP= 15 MeV), and probe the spin-coherence of the defects. Electron paramagnetic resonance methods show that such irradiation generates the VB- centers. Spin-relaxation times (T1 and T2) of VB- spin ensembles created by proton irradiation are determined to be 20 μs and 4 μs, respectively

A comparative study of the formation mechanism of a single-pulse echo and its analog formed jointly by radio-frequency and two magnetic video-pulses, when their amplitude exceeds the pinning force of domain walls, is carried out. The results obtained support the assumption that the single-pulse echo signal is formed by the mechanism of local field distortions at nuclei in domain walls when they are displaced by RF pulse fronts due to the inhomogeneity of the hyperfine field and the NMR amplification factor in the domain wall