Resistivity, Hall effect and Shubnikov-de Haas oscillations in CeNiSn

TL;DR

This study investigates the low-temperature electronic properties of CeNiSn, revealing heavy quasiparticles, anomalous resistivity behavior, and multiple Shubnikov-de Haas oscillations indicating complex Fermi surface changes under magnetic fields.

Contribution

It provides detailed measurements of resistivity, Hall effect, and quantum oscillations in CeNiSn at very low temperatures and high magnetic fields, highlighting field-induced electronic structure modifications.

Findings

Quadratic resistivity with a large coefficient below 0.16 K

Observation of SdH oscillations with frequencies around 100 T and 300-400 T

Detection of field-dependent anomalies and possible Fermi surface changes

Abstract

The resistivity and Hall effect in CeNiSn are measured at temperatures down to 35 mK and in magnetic fields up to 20 T with the current applied along the {\it b} axis. The resistivity at zero field exhibits quadratic temperature dependence below $\sim$0.16 K with a huge coefficient of the $T^2$ term (54 $\mu$$\Omega$cm/K$^2$). The resistivity as a function of field shows an anomalous maximum and dip, the positions of which vary with field directions. Shubnikov-de Haas (SdH) oscillations with a frequency {\it F} of $\sim$100 T are observed for a wide range of field directions in the {\it ac} and {\it bc} planes, and the quasiparticle mass is determined to be $\sim$10-20 {\it m}$_e$. The carrier density is estimated to be $\sim10^{-3}$ electron/Ce. In a narrow range of field directions in the {\it ac} plane, where the magnetoresistance-dip anomaly manifests itself clearer than in other field directions, a higher-frequency ($F=300\sim400\text{T}$) SdH oscillation is found at high fields above the anomaly. This observation is discussed in terms of possible field-induced changes in the electronic structure.