Magnetic phase diagram and vanishing topological Hall effect in the chiral antiferromagnet Co_2−x Pd _x Mo₃N

Abstract The magnetic phase diagram and topological Hall effect (THE) are studied by magnetization and transport measurements for chiral antiferromagnet (AFM) Co 2- x Pd x Mo 3 N ( x = 0–1.61) thin films with the filled β -Mn-type chiral structure, which reveals the rich phase diagram in the temperature versus Pd content x plane, where a collinear AFM, a canted AFM, and a low-temperature phase below 50 K are found to exist. For thin films with x = 1.01–1.61, the low-temperature phase shows prominent THE. The formation of the canted AFM phase with the Néel temperature up to 325 K is observed with vanishing THE. These findings establish the chiral antiferromagnetic molybdenum nitrides as a fertile playground for exploring the interplay between chiral antiferromagnetism, topological spin textures, and novel magnetotransport phenomena.