Assessment of Co-Ga alloys magnetostriction

Highlights: • Magnetostriction of Co-Ga alloys studied for the first time. • Ferromagnetic Co-Ga alloys have negative saturation magnetostriction λ_s. • Co-33Ga alloy magnetostriction saturates for small fields. - Abstract: The magnetostriction of Co-Ga alloys: Co-14Ga, Co-24Ga and Co-33Ga (atomic), is studied at room temperature for the first time. All three alloys are ferromagnetic. Co-14Ga microstructure is biphasic, a mixture of ε (hcp) and α (fcc) phases. Co-24Ga presents three phases ε, α and β (ordered bcc) and Co-33Ga is single β phase alloy. It was found that all three alloys present negative saturation magnetostriction λ_s. The most interesting material for applications would be the alloy Co-33Ga since the magnetostriction saturates for a small field.