Enhancement of domain-wall mobility detected by NMR at the angular momentum compensation temperature
The angular momentum compensation temperature TA of ferrimagnets has attracted much attention because of high-speed magnetic dynamics near TA. We show that NMR can be used to investigate domain-wall dynamics near TA in ferrimagnets. We performed Fe57-NMR measurements on the ferrimagnet Ho3Fe5O12 with TA=245 K. In a multidomain state, the NMR signal is enhanced by domain-wall motion. We found that the NMR signal enhancement shows a maximum at TA in the multidomain state. The NMR signal enhancement occurs due to increasing domain-wall mobility toward TA. We develop the NMR signal enhancement model involves domain-wall mobility. Our study shows that NMR in multidomain state is a powerful tool to determine TA, even from a powder sample and it expands the possibility of searching for angular momentum-compensated materials.