Spin–phonon interaction effects in pure and Fe-doped antiferromagnetic Cr2O3 nanoparticles

•We have studied theoretically the magnetic and phonon properties of Cr2O3 nanoparticles.•It is shown that with decreasing of particle size the magnetization increases whereas the Neel temperature decreases.•The phonon energy ωω of the A1g mode has a kink at TN due to the strong spin–phonon interaction.•ωω increases with decreasing of particle size.•Fe-dopant concentration reduces the phonon energy.

We have studied the temperature and size dependence of the magnetic and phonon properties of pure and Fe-doped antiferromagnetic Cr2O3 nanoparticles using a microscopic model and a Green's function technique. The magnetization M increases whereas the Neel temperature TN decreases with decreasing of particle size. The phonon energy ωω has a kink at TN due to the strong spin–phonon interaction. It increases with decreasing of particle size. Fe-dopant concentration reduces ωω.