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Ê Ú ¿½ Å Ý ¾¼½¼ ÔØ ¾  ÒÙ ÖÝ ¾¼½½ ×ØÖ ØCompounds with the general formula Mg 1− Al B 2 were obtained by two-step ceramic synthesis. All compounds were characterized by X-ray diffraction, NMR spectroscopy, and by four point probe resistivity measurements in various magnetic fields method. The diborides unit cell parameters were determined as a function of the Al mole fraction. With the vaues of up to 0.40 (where is the composition of the stock prepared for sintering), the unit cell parameters of Mg 1− Al B 2 are similar to those of pure MgB 2 and the superconducting transition temperature was lowered. For stock compositions of 0 25 ≤ ≤ 0 60, the products contain a superstructure, also superconducting phase, which becomes the only product at = 0 50, and at > 0 60 this phase is replaced by AlB 2 -based solid solutions.

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