Interplay between Charge and Magnetic Ordering in YbPd

Abstract

The pressure-temperature phase diagram of an intermediate-valence compound YbPd was revealed via simultaneous ac-calorimetry and electrical resistivity measurements. Two successive structural phase transition temperatures, $T_1$ = 125 K and $T_2$ = 110 K, are found to decrease with increasing pressure. The magnetic ordering transition at $T_{\mathrm{N}}sim$ 1.9 K decreases monotonically up to 1.7 GPa and disappears discontinuously at $P_{\mathrm{c}}sim$ 1.9 GPa, where the structural phase transition at $T_2$ is also suppressed. At $P_{\mathrm{c}}$, enhancement of the effective mass and residual resistivity are observed. Another probable magnetic phase transition, however, is found to take place at $T_{\mathrm{ML}}sim$0.3 K and smoothly varies even when crossing $P_{\mathrm{c}}$. Structural phase transitions at ambient pressure were also studied by a single crystal X-ray diffraction measurement. Below $T_2$, a tetragonal lattice distortion with doubling of the unit cell along the c-axis is observed, and thus there are two inequivalent Yb-sites below $P_{\mathrm{c}}$. These results indicate that one Yb-site, having larger valence configuration and thus smaller Kondo temperature, orders at $T_{\mathrm{N}}$. The other phase transition at $T_{\mathrm{ML}}$ seems to couple to the crystal structure for $T_2<T<T_1$. YbPd is a unique system exhibiting magnetic orderings in metallic charge-ordered Yb systems.

7 pages, 5 figures, to be published in J. Phys. Soc. Jpn

References in corpus (4)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Pressure-induced unconventional superconductivity in the heavy-fermion antiferromagnet CeIn3: An 115In-NQR study under pressure
• Anomalous Pressure Dependence of Kadowaki-Woods ratio and Crystal Field Effects in Mixed-valence YbInCu4
• Kondo engineering : from single Kondo impurity to the Kondo lattice

Cited by in corpus (3)

• Charge ordering in the intermediate valence magnet YbPd
• Pressure-induced ferromagnetism with strong Ising-type anisotropy in YbCu${}_2$Si${}_2$
• Anomalous pressure dependence of the bulk modulus and Yb valence in cubic YbPd