EuNiGe₃, an anisotropic antiferromagnet.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Magnetism

Background:

• Polycrystalline samples of EuNiGe3 previously limited the study of its magnetic properties.
• The BaNiSn3-type structure is non-centrosymmetric, suggesting potential for anisotropic behavior.

Purpose of the Study:

• To synthesize single crystals of EuNiGe3 for detailed anisotropic magnetic property investigations.
• To understand the magnetic ordering and phase transitions in EuNiGe3.

Main Methods:

• Single crystal growth using In flux.
• Magnetic susceptibility, heat capacity, and electrical resistivity measurements.
• (H,T) phase diagram construction.
• (151)Eu Mössbauer spectroscopy.

Main Results:

• EuNiGe3 orders antiferromagnetically at 13.2 K.
• Anisotropic magnetization behavior observed with distinct spin-flip transitions along the ab-plane (6.2 T) and c-axis (4.1 T).
• Two metamagnetic transitions observed along the c-axis.
• Mössbauer spectra indicate an incommensurate AFM phase transitioning to a commensurate AFM phase near 10.5 K.

Conclusions:

• Single crystalline EuNiGe3 displays complex anisotropic magnetic ordering and field-induced transitions.
• A model of anisotropic exchange and dipole-dipole interactions partially explains the observed magnetization.
• The study provides a comprehensive (H,T) phase diagram and insights into the magnetic structure of EuNiGe3.