Static magnetic susceptibility of radiopaque NiTiPt and NiTiEr

Highlights: • Magnetic susceptibility of NiTiPt and NiTiEr were measured. • Effect of thermal and mechanical treatments on magnetic susceptibility was evaluated. • Effect of increasing rare-earth content on magnetic susceptibility was determined. • Comparison to commonly used alloy NiTi and feasibility of the usage of ternary alloys as medical implants. • NiTiPt and NiTiEr are paramagnetic and safe with respect to magnetic resonance imaging. Magnetic properties of metallic alloys used in biomedical industry are important for the magnetic resonance imaging (MRI). If the alloys were to be used for long term implants or as guiding devices, safety of the patient as well as the medical staff has to be ensured. Strong response to the external magnetic field can cause mechanical damage to the patients body. In this paper we present magnetic susceptibility of nickel rich, ternary NiTiPt and NiTiEr to static magnetic field. We show that the magnetic susceptibility of these radiopaque alloys has values in low paramagnetic region comparable to the binary nickel-titanium. Furthermore, we studied the effect of the thermal and mechanical treatments on magnetic properties. Despite deviation from linear $M\left(H\right)$ treated samples spanning small region around $H=0$, the linearity of the $M\left(H\right)$ and $\chi =\text{d}M/\text{d}H$ values suggest that these ternary alloys are safe to use under MRI conditions.