ساخت سيم ابررساناي MgB2

MgB₂ superconductors are considered a suitable alternative to low-temperature superconducting (LTS) alloys in legacy cryogen-free magnets due to their relatively high critical temperature, low raw material costs, an‎d low density. However, the commercial use of these materials depends on improving the critical current density (Jc ), particularly in high magnetic fields. The main objective of this research was to develop, industrialize, an‎d localize high-performance MgB₂ wires an‎d bulk materials for liquid-helium-free applications, with enhanced performance in external magnetic fields. In the first stage, bulk MgB₂ samples were prepared using the solid-state reaction method, an‎d their structural an‎d superconducting properties were investigated. Subsequently, single-core wire samples were fabricated using the Powder-In-Tube (PIT) method. The effect of various heat treatment conditions, including sintering temperature an‎d duration, on microstructural properties an‎d critical current density was examined. The results indicated that heat treatment within the range of 680℃ to 900℃ for 2 to 4 hours leads to optimal Jc values. Furthermore, the effect of two types of impurities, carbon an‎d nickel oxide, on the magnetic behavior of MgB₂ was studied using a Vibrating Sample Magnetometer (VSM). The pure sample exhibited a narrow hysteresis loop (weak pinning). While carbon provided a slight improvement, nickel oxide significantly broadened the hysteresis loop an‎d increased the remanent magnetization.

پيمان صاحب سرا , حميده شاكري پور

پرويز كاملي , مسعود عطاپور