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Register a new userThe doping dependence of superconductivity of (Ca1-xNax)Fe2As2
التعتيم الاعتمادي للسوبر كوندكتيوتي لـ (Ca1-xNax)Fe2As2
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وقد تم تحضير وتشخيص الكرومات المنفردة CaFe2As2 والبوليكريستالات (Ca1-xNax)Fe2As2 (0 < x < 0.66) باستخدام القياسات الهندسية والمغناطيسية والنقل الكهربائي والحرارة. تظهر هذه القياسات أن تحول الهندسي / المغناطيسي في CaFe2As2 في 165 درجة كلوري تم تخفيضه بشكل متزايد بالتحميل الناتي وأن السوبر كوندوكتيبيليتي يمكن أن يتحقق في منطقة التحميل الواسعة. ل 0.3 < x < 0.36، تشير الحساسيات المغناطيسية إلى إمكانية توازن الجهد الكتلي الذري (SDW) والسوبر كوندوكتيبيليتي. وتم التعرف على المرحلة السوبر كوندوكتيبيلية المتعلقة بمستوى التحميل الناتي في (Ca1-xNax)Fe2As2 للحجم المعتاد x = 0.36، 0.4، 0.5، 0.6 و 0.66، بحيث تشمل Tc = 17 درجة كلوري، 19 درجة كلوري، 22 درجة كلوري، 33 درجة كلوري، و 33 درجة كلوري على التوالي. وتم دراسة تأثير المجال المغناطيسي على تحولات السوبر كوندوكتيبيليتي للعينات التي تحمل الحجم x = 0.66 مع حدود المجال الكبيرة العليا Hc2 تقريبا 103 تولز، وبالتالي تم عرض مخطط للجهد الكتلي الذري والسوبر كوندوكتيبيليتي باعتماد مستوى التحميل.
Single crystalline CaFe2As2 and (Ca1-xNax)Fe2As2 polycrystals (0 < x < 0.66) are synthesized and characterized using structural, magnetic, electronic transport, and heat capacity measurements. These measurements show that the structural/magnetic phase transition in CaFe2As2 at 165 K is monotonically suppressed by the Na doping and that superconductivity can be realized over a wide doping region. For 0.3 < x < 0.36, the magnetic susceptibilities indicate the possible coexistence of the spin density wave (SDW) and superconductivity. Superconducting phases corresponding to the Na doping level in (Ca1-xNax)Fe2As2 for nominal x = 0.36, 0.4, 0.5, 0.6, and 0.66, with Tc = 17 K, 19 K, 22 K, 33 K, and 33 K, respectively, are identified. The effects of the magnetic field on the superconductivity transitions for x = 0.66 samples with high upper critical fields Hc2 approx 103 T are studied, and a phase diagram of the SDW and superconductivity as a function of the doping level is thus presented.
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