We measured the heat capacity, magnetic susceptibility, magnetization, magnetoelectric effect, and optical spectra of samarium chromium borate crystals. It was found that, in $\mathrm{Sm}{\mathrm{Cr}}_3{\left(\mathrm{B}{\mathrm{O}}_3\right)}_4$ single crystals, structures with the space groups $R32$ and $C2/c$ may coexist. Magnetic phase transitions were discovered at temperatures $T_{\mathrm{N}1}=7.8\pm 0.5\mathrm{K}$, $T_{\mathrm{N}2}=6.7\pm 0.5\mathrm{K}$, and $T_3=4.3\pm 0.2\mathrm{K}$, and assumptions about their nature were made. Based on the high-resolution optical spectra and magnetometry data, the crystal-field parameters in the ${\mathrm{Sm}}^{3+}$ and ${\mathrm{Cr}}^{3+}$ positions and the parameters of ${\mathrm{Cr}}^{3+}\text{−}{\mathrm{Cr}}^{3+}$ and ${\mathrm{Cr}}^{3+}\text{−}{\mathrm{Sm}}^{3+}$ exchange interactions were determined. The magnetic properties of the quasi-one-dimensional chromium subsystem were analyzed in the frame of the previously developed self-consistent four-particle cluster model. Despite a strong suppression of ${\mathrm{Cr}}^{3+}$ magnetic moments by the interchain antiferromagnetic exchange interactions, the contributions of the chromium subsystem to the bulk magnetization are dominant.

• Received 22 June 2021
• Revised 23 September 2021
• Accepted 6 October 2021

DOI:https://doi.org/10.1103/PhysRevMaterials.5.104413