Anomalous pressure dependence of the bulk modulus and Yb valence in cubic YbPd
Abstract
We investigate the Yb valence instabilities in the strongly correlated YbPd compound using resonant x-ray emission spectroscopy as a function of pressure across the charge-order (CO) transition. At a low temperature (T=30K) in the CO phase, the Yb 4f valence remains nearly constant up to a pressure PL=1.5 ±0.2GPa, and then increases gradually at higher pressures. In contrast, at room temperature in the normal phase, an anomalous decrease of the Yb 4f valence is observed, without any accompanying structural phase transition. This behavior is corroborated by a systematic pressure-dependent decrease of the unit-cell volume. Based on a Birch-Murnaghan analysis, the compressibility indicates hardening of the lattice with applied pressure up to a distinct kink seen at PK=1.6 ±0.2GPa. In contrast, for P > PK, the Yb 4f valence saturates, and the compressibility reveals a counterintuitive pressure-induced softening. The results show a minimum in the compressibility of YbPd (with f0─f1 hole-type mixed valence), reminiscent of the maximum in compressibility seen in the γ─α first-order isostructural phase transition in cerium (with f0─f1 electron-type mixed valence).
Related
- Implicit size dependence of the valence electron concentration criterion in high-entropy alloys
- Crucial role of magnetic dipole and anomalous field dependence in NiPS3
- Anomalous temperature dependence in phase transitions via ballistic coalescence
- Robust Anomalous Hall Effect in Epitaxial Cubic D03-Fe3Ge Nanoplates Grown by Chemical Vapor Deposition
- Anomalous Pressure-Enhanced Polarization in Sliding Ferroelectrics
BibTeX
@article{chiogo2026anomalous,
title = {{Anomalous pressure dependence of the bulk modulus and Yb valence in cubic YbPd}},
author = {Bodry Tegomo Chiogo and Victor Balédent and Jean-Pascal Rueff and Ethan Saïman and Victor Porée and Thierry Schweitzer and Deniz Wong and Christian Schulz and Thomas Mazet and Ashish Chainani and Daniel Malterre and Klaus Habicht},
journal = {Physical Review Research},
year = {2026},
month = jul,
doi = {10.1103/ftks-31jr},
eprint = {2601.05766},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05742125v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Anomalous pressure dependence of the bulk modulus and Yb valence in cubic YbPd
AU - Bodry Tegomo Chiogo
AU - Victor Balédent
AU - Jean-Pascal Rueff
AU - Ethan Saïman
AU - Victor Porée
AU - Thierry Schweitzer
AU - Deniz Wong
AU - Christian Schulz
AU - Thomas Mazet
AU - Ashish Chainani
AU - Daniel Malterre
AU - Klaus Habicht
PY - 2026
DA - 2026/07/13
JO - Physical Review Research
DO - 10.1103/ftks-31jr
UR - https://hal.science/hal-05742125v1
AB - We investigate the Yb valence instabilities in the strongly correlated YbPd compound using resonant x-ray emission spectroscopy as a function of pressure across the charge-order (CO) transition. At a low temperature (T=30K) in the CO phase, the Yb 4f valence remains nearly constant up to a pressure PL=1.5 ±0.2GPa, and then increases gradually at higher pressures. In contrast, at room temperature in the normal phase, an anomalous decrease of the Yb 4f valence is observed, without any accompanying structural phase transition. This behavior is corroborated by a systematic pressure-dependent decrease of the unit-cell volume. Based on a Birch-Murnaghan analysis, the compressibility indicates hardening of the lattice with applied pressure up to a distinct kink seen at PK=1.6 ±0.2GPa. In contrast, for P > PK, the Yb 4f valence saturates, and the compressibility reveals a counterintuitive pressure-induced softening. The results show a minimum in the compressibility of YbPd (with f0─f1 hole-type mixed valence), reminiscent of the maximum in compressibility seen in the γ─α first-order isostructural phase transition in cerium (with f0─f1 electron-type mixed valence).
SN - 2643-1564
SN - 2643-1564
ER -