High-pressure, transport, and thermodynamic properties of ${\text{CeTe}}_3$

We have performed high-pressure, electrical resistivity, and specific heat measurements on ${\text{CeTe}}_3$ single crystals. Two magnetic phases with nonparallel magnetic easy axes were detected in electrical resistivity and specific heat at low temperatures. We also observed the emergence of an additional phase at high pressures and low temperatures and a possible structural phase transition detected at room temperature and at 45 kbar, which can possibly be related with the lowering of the charge-density wave transition temperature known for this compound.

Figure 1

(Color online) Electrical resistivity versus temperature at various pressures for ${\text{CeTe}}_3$ single crystals. Upper panel: hydrostatic cell experimental results. The inset shows the low-range, displaying the onset of the magnetic order as $T_{1,\rho }$. Lower panel: Bridgman-anvil cell results. The inset shows $T_{1,\rho }$, along with the new ordering temperature $T_{2,\rho }$, indicated in the figure for the first Bridgman run (for the 152 kbar curve) and for the second Bridgman run (in black, dashed curve).

Figure 2

(Color online) Electronic and magnetic contribution to the specific heat for different magnetic fields applied along the $b$ axis of the ${\text{CeTe}}_3$ crystals. $T_{1,C}$ corresponds to the field-independent ordering temperature centered near 3 K, while $T_{2,C}$ denotes the field-dependent feature below 1.5 K. In the lower inset, the solid curve (blue) corresponds to the electronic and magnetic entropy in zero magnetic field and the horizontal dashed line corresponds to the value $R\text{ln}2\text{J}/\text{mol}\text{K}$. The upper inset shows a schematic diagram of the crystal structure of ${\text{CeTe}}_3$ and the direction of the applied magnetic field in the specific-heat experiment.

Figure 3

(Color online) Left: field dependence of the magnetic ordering temperatures $T_{1,\rho }$ and $T_{2,C}$ of ${\text{CeTe}}_3$ for magnetic fields applied perpendicular and parallel to the $b$ axis. A logarithmic temperature scale was chosen to emphasize the curvature of $T_2$ vs $H$. Right: temperature dependence of the electrical resistivity near $T_1$ for magnetic fields applied parallel (upper right: 0, 3, 6, and 9 T) and perpendicular (lower right: 0, 0.5, 1, 1.5, 3, 4, 5, 6, and 9 T) to the $b$ axis of the crystals. The arrows mark the position of $T_1$. The numbers on each curve denote the value of the applied magnetic field in tesla. For the lower-right panel, arrows and numbers for fields of 0.5 and 1 T are not displayed for better clarity.

Figure 4

(Color online) Temperature versus pressure phase diagram for ${\text{CeTe}}_3$ (note the logarithmic temperature scale). $T^{\ast }$ characteristic temperature associated with the “humplike” feature in $\rho \left(T\right)$, possible origins of which are discussed in the text; $T_1$ magnetic ordering temperature; $T_2$ ordering temperature (probably magnetic). The vertical dashed line separates the $T\text{−}P$ phase diagram into two regions in which $T^{\ast }$, $T_1$, and $T_2$ all have distinctly different pressure dependencies. We grouped in a single low-temperature magnetic phase the critical temperatures $T_2$ obtained from measurements of the electrical resistivity under pressure and specific heat at ambient pressure, although they might have different origins. Inset: room-temperature evolution of the electrical resistance as the pressure was increased. The abrupt jump at 45 kbar may be due to a structural phase transition.