New high-field superconductor, V2Hf/sub x/Zr/sub 1-x/

C-15 type structure V2HfxZr1−x shows a high resistive critical field exceeding 200 kOe at 4.2°K whenever x>0.3. The highest transition temperature, 10.1°K, and critical field, 230 kOe, are achieved with the composition V2Hf0.5Zr0.5. For this material the critical current density at 4.2°K and 130 kOe is as high as 1×105 A/cm2, which should make it of interest for practical use at high fields.