# Low Curie-temperature ferromagnetic phase in SmPt2Cd20 possibly accompanied by strong quantum fluctuations

## TL;DR

This study investigates SmPt2Cd20, a cubic compound with an exceptionally low Curie temperature of 0.64 K, revealing strong quantum fluctuations and proximity to a ferromagnetic quantum critical point through resistivity, magnetization, and specific heat measurements.

## Contribution

It reports the discovery of a low-temperature ferromagnetic transition and quantum fluctuations in SmPt2Cd20, highlighting its potential as a rare cubic system near a ferromagnetic quantum critical point.

## Key findings

- Ferromagnetic transition at 0.64 K in SmPt2Cd20
- Strong quantum fluctuations indicated by specific heat data
- Resistivity follows a T^{0.74} power law below 2 K

## Abstract

Electrical resistivity, magnetization and specific heat have been measured for single crystals of SmPt$_{2}$Cd$_{20}$. It has been found that SmPt$_{2}$Cd$_{20}$ exhibits a ferromagnetic (FM) transition at $T_{\rm C} = 0.64$ K, the lowest among cubic compounds. Specific heat divided by temperature increases with decreasing temperature even below $T_{\rm C}$ and attains 4.5 J/mol K$^{2}$ at 0.26 K, implying substantial magnetic quantum fluctuations. An analysis of the magnetic entropy suggests the crystalline-electric-field splitting of the Sm $J = 5/2$ multiplet with a $\Gamma_{7}$ doublet ground state and a $\Gamma_8$ quartet excited state (the excitation energy of $\sim30$ K). The electrical resistivity shows a power-law behavior with $T^{0.74}$ below 2 K without showing any noticeable anomaly at $T_{\rm C}$. SmPt$_{2}$Cd$_{20}$ is regarded as a rare cubic system that is located in the vicinity of a FM quantum critical point.