Two terbium tellurides, ${\mathrm{TbTe}}_3$ and ${\mathrm{Tb}}_2{\mathrm{Te}}_5$, were studied by means of thermodynamics, ultrafast pump-probe spectroscopy, and torque magnetometry. While the crystal structure and some physical properties of ${\mathrm{TbTe}}_3$ were established previously, the crystal structure of ${\mathrm{Tb}}_2{\mathrm{Te}}_5$ is reported based on the low-temperature (100 K) single crystal x-ray diffraction experiment. ${\mathrm{Tb}}_2{\mathrm{Te}}_5$ crystallizes in orthorhombic Cmcm space group with $a=4.3009\left(17\right)$, $b=43.107\left(18\right)$, $c=4.3016\left(17\right)\AA$, $V=797.5\left(6\right){\AA }^3$, and $Z=4$. In contrast to ${\mathrm{TbTe}}_3$, which experiences three successive magnetic phase transitions, ${\mathrm{Tb}}_2{\mathrm{Te}}_5$ orders antiferromagnetically in two steps at $T_{\mathrm{N}1}=9.0$ K and $T_{\mathrm{N}2}=6.8$ K, both readily suppressed by an external magnetic field. The third transition in ${\mathrm{TbTe}}_3$ is due to the interaction of the magnetic subsystem with the charge density waves. The interaction of magnetic and electronic subsystems in ${\mathrm{Tb}}_2{\mathrm{Te}}_5$ has been revealed by the pump probe. Torque measurements of ${\mathrm{TbTe}}_3$ show that the magnetic moments of Tb are oriented predominantly in the $ac$ plane at high temperatures and switch to the $b$ axis at low temperatures. In ${\mathrm{Tb}}_2{\mathrm{Te}}_5$, the magnetic moments of Tb are oriented predominantly in the $ac$ plane at low temperatures.

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• Charge density waves
• 2-dimensional systems
• Antiferromagnets
• Torque magnetometry