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تسجيل مستخدم جديدالتغيرات الهيكلية والخصائص المغناطيسية للمغناطيس الأنتي فيرومغناطيسي Cs2CuCl4-xBrx
Structural variations and magnetic properties of the quantum antiferromagnets Cs2CuCl4-xBrx
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بالاعتماد على ظروف النمو البلوري، يمكن العثور على هيكل اورثورومبيك (نوع O) أو هيكل تتراجونال (نوع T) في الحلول الصلبة Cs2CuCl4-xBrx (0 < x < 4). هنا نقدم قياسات للحساسية المغناطيسية المعتمدة على الحرارة والتجمع الحراري الثابت على المركبات النوع T x = 1.6 و 1.8 ونقارن هذه النتائج مع الخصائص المغناطيسية التي تم الحصول عليها مؤخرا للنوع O بواسطة Cong et al.، Phys. Rev. B 83، 064425 (2011). وقد وجد أن النظم تشهد خصائص مغناطيسية بعيدة عن الشبيهة التي يمكن تعيينها للاختلافات في توأمة كو في هذه النواة الهيكلية الاثنتين. في حين أن المركبات التتراجونالة يمكن تصنيفها كمغناطيسيات نصف ثنائية الأبعاد، التي تتميز بطبقات مغناطيسية مشتركة مع ربط ضد مغناطيسي ضعيف بين الطبقات، فإن المواد الاورثورومبية، وخصوصا المركبات الحدودية x = 0 و 4، هي نظم عينة لمغناطيسيات هايزنبرغ محبطة ثنائية الأبعاد.
Depending on the crystal growth conditions, an orthorhombic (O-type) or a tetragonal (T-type) structure can be found in the solid solution Cs2CuCl4-xBrx (0 < x < 4). Here we present measurements of the temperature-dependent magnetic susceptibility and isothermal magnetization on the T-type compounds x = 1.6 and 1.8 and compare these results with the magnetic properties recently derived for the O-type variant by Cong et al., Phys. Rev. B 83, 064425 (2011). The systems were found to exhibit quite dissimilar magnetic properties which can be assigned to differences in the Cu coordination in these two structural variants. Whereas the tetragonal compounds can be classified as quasi-2D ferromagnets, characterized by ferromagnetic layers with a weak antiferromagnetic inter-layer coupling, the orthorhombic materials, notably the border compounds x = 0 and 4, are model systems for frustrated 2D Heisenberg antiferromagnets
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Starting from Cs2CuCl4 and Cs2CuBr4 our project focuses on the growth of the Cs2CuCl4-xBrx mixed crystals from aqueous solution and the investigation of the occurring structural variations. The well known orthorhombic structure (space group Pnma) of
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We report magnetization and specific heat measurements in the 2D frustrated spin-1/2 Heisenberg antiferromagnet Cs2CuCl4 at temperatures down to 0.05 K and high magnetic fields up to 11.5 T applied along a, b and c-axes. The low-field susceptibility
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