Signature of partially frustrated moments and a new magnetic phase in CeNiGe2

TL;DR

This study investigates CeNiGe2, revealing a magnetic field-induced new phase caused by partial frustration and spin fluctuations, with no quantum critical point, challenging existing heavy fermion models.

Contribution

It uncovers a novel high-field antiferromagnetic phase in CeNiGe2 driven by partial frustration, not explained by the Doniach model.

Findings

Magnetic field merges two antiferromagnetic peaks into one.

A new magnetic feature appears above 1 T at 3.6 K.

No quantum critical point observed in CeNiGe2.

Abstract

We report the magnetic, thermodynamic, and transport properties of a heavy fermion compound CeNiGe2. This compound undergoes two antiferromagnetic transitions around 4.1 and 3 K. It is observed in heat capacity that as magnetic field is increased to ~ 1 T, the two peak merge into a single peak around 3 K. However this peak is not suppressed under the application of magnetic field. Instead a new feature develops at 3.6 K above 1 T. The magnetic field induced new feature is investigated through entropy evolution, magnetic Gruneisen parameter and resistivity studies. These studies emphasis the fact that partial magnetic frustration due to field induced spin fluctuation is responsible for this observed feature. This partially frustrated regime develops a new antiferromagnetically ordered phase at high fields. In this compound magnetic field induced QCP is absent implying that the behavior of CeNiGe2 is not in accordance to Doniach model proposed for heavy fermions compounds.