Chemical Pressure in the Distorted Kagome Material ErAgGe

The rare earth intermetallic family REAgGe (RE= Rare earth elements) has received significant attention recently in the condensed matter community as potential magnetic topological semimetals with a unique and tunable distorted kagome lattice. These materials crystallize in the non-centrosymmetric P-62m space group, where the loss of inversion symmetry and intrinsic kagome distortion generate a platform to investigate the relationship between crystalline symmetry, magnetic order and electronic topology. Materials in this family can exhibit strong in plane magnetic anisotropy that acts as the primary driver of its coupled magnetic and electronic states such as the kagome spin ice HoAgGe which features a large anomalous Hall effect. In order to further explore these effects in the REAgGe distorted kagome magnet family, here we have investigated ErAgGe which similarly shows a strong in plane magnetic anisotropy. Previous powder neutron diffraction measurements revealed an easy axis which lies in the ab-plane and a collinear antiferromagnetic structure. However, the reported magnetic structure cannot explain our magnetization, transport data and preliminary single crystal polarized neutron diffraction results. The anisotropy of magnetism and possible non-collinear magnetic structure is evident from our magnetization data, showing nonlinear variation at low field. Our resistivity measurements likewise reveal the field induced transition. To further manipulate the distorted kagome lattice we have applied a positive chemical pressure by the partial substitution for Si on the Ge atomic site and reveal its influence on the magnetization and field-induced transitions. These findings offer new insights into the REAgGe rare-earth intermetallic family, revealing the intricate interplay between magnetism, topology, and lattice distortions.