Temperature dependent spin and orbital magnetization in TbCo2: Magnetic Compton scattering and first-principles investigations

• Presented temperature dependent spin momentum densities in TbCo2.
• Explored spin and orbital magnetic moments at different sites.
• Contribution of local and itinerant moments in TbCo2 is explained.
• First-principles calculations are performed to supplement the experiment.

Spin-polarized Compton profiles of TbCo2 have been measured to elucidate the interesting behavior of spin and orbital moments at different temperatures. The magnetic Compton profiles (MCPs) have been analyzed in terms of site specific spin moments due to Tb-4f electrons, Co and itinerant electrons. The temperature dependence of the orbital moment has been deduced using Compton and magnetometry data ranging between 6 and 300 K. The present data exhibit a decrease in the ratio of orbital to spin moments from 43.9% to 35.0% (while going from 6 to 300 K). First-principles calculations within DFT + U scheme have also been performed to confirm the spin-, orbital- and site specific-magnetic moments in TbCo2. An antiparallel exchange coupling between the Tb-4f and Co spin moments is found. The orbital moment is found to have a parallel coupling with the Tb spin moment, as evident from the experimental MCPs. From first-principles data it is seen that the orbital moments of Tb and Co sites are antiparallel to each other, as in the case of their spin magnetic moments. The present experimental study also shows an existence of an itinerant moment which is coupled ferromagnetically with the Tb-4f spin moment.

Figure optionsDownload as PowerPoint slide