Magnetic field-induced quantum critical point in YbPtIn and YbPt$_{0.98}$In single crystals

TL;DR

This study investigates how slight stoichiometric changes in YbPtIn compounds influence their magnetic ordering and reveals a field-induced quantum critical point in both materials, with critical fields affected by composition.

Contribution

It provides detailed anisotropic measurements on YbPtIn and YbPt$_{0.98}$In single crystals, demonstrating the impact of stoichiometry on quantum critical behavior and critical magnetic fields.

Findings

Stoichiometry drastically affects ordering temperatures.

A field-induced quantum critical point is observed in both compounds.

Critical magnetic fields are reduced in the slightly off-stoichiometric compound.

Abstract

Detailed anisotropic (H$\parallel$ab and H$\parallel$c) resistivity and specific heat measurements were performed on online-grown YbPtIn and solution-grown YbPt$_{0.98}$In single crystals for temperatures down to 0.4 K, and fields up to 140 kG; H$\parallel$ab Hall resistivity was also measured on the YbPt$_{0.98}$In system for the same temperature and field ranges. All these measurements indicate that the small change in stoichiometry between the two compounds drastically affects their ordering temperatures (T$_{ord}\approx3.4$ K in YbPtIn, and $\sim2.2$ K in YbPt$_{0.98}$In). Furthermore, a field-induced quantum critical point is apparent in each of these heavy fermion systems, with the corresponding critical field values of YbPt$_{0.98}$In (H$^{ab}_c$ around 35-45 kG and H$^{c}_c\approx120$ kG) also reduced compared to the analogous values for YbPtIn (H$^{ab}_c\approx60$ kG and H$^{c}_c>140$ kG)