M.Sc. Tezi Görüntüleme | |||||||||||||||||||||
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| Summary: MgB2 bulk superconductors were prepared from magnesium powder (%99.8), amorphous boron powder (>%98), malic acid (C4H6O5) and toluene (C7H8) by using "Two-Step Solid State Reaction Method". Structural analysis of all samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Magnetization hysteresis loops (M–H) for determination of Jc were measured using a vibrating sample magnetometer (VSM) of the Quantum Design PPMS system. The magnetic Jc values were derived from the height of the magnetization loop using the Bean’s critical state model. Magnetic levitation force measurements at low temperatures were performed at solid state research laboratory in Recep Tayyip Erdogan University using the cryostat system.% 4 malic acid adding ratio exhibited the best significant improvement for magnetic levitation force. A sample which prepared by % 4 adding ratio levitated an object which was 950 times heavier than its weight. We observed that % 4 and % 6 adding ratio acts as significant pinning centers. Key Words: MgB2, Magnetic Levitation Force, Malic Acid, C4H6O5, Two Step Solid State Reaction, XRD, PPMS
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