Development of the magnetism in the solid solution of the candidate Weyl semimetals Ce$_x$Pr$_{1-x}$AlGe

Abstract

We investigate the macroscopic and microscopic physical properties of the solid solution of Ce$_{1-x}$Pr$_{x}$AlGe. The series tunes from CeAlGe with its multi-$\vec{k}$ structure and a major Moment in the ab-plane, to PrAlGe with an easy-c-axis ferromagnetic ground state co-existing with a low density of nanoscale textured magnetic Domain walls. Using AC-, DC-susceptiblity, resistivity, specific heat, muon spin relaxation/rotation and neutron scattering we analyze the magnetic ground state of the series. We provide further evidence supporting our previous claim for spin-glass like properties in pure PrAlGe. With introduction of Pr to CeAlGe the finite magnetic field required to stabilize the topological multi-$\vec{k}$ magnetic phase for $x=0$ becomes suppressed. The crossover between the two end-member ground states occurs in the vicinity of $x=0.3$, a region where we further anticipate the field-induced topological magnetic phase for $x < 0.3$ to become the zero field ground state.