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تسجيل مستخدم جديدElectronic Instabilities in Shape-Memory Alloys
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Using a variety of thermodynamic measurements made in magnetic fields, we show evidence that the diffusionless transition (DT) in many shape-memory alloys is related to significant changes in the electronic structure. We investigate three alloys that show the shape-memory effect (In-24 at.% Tl, AuZn, and U-26 at.% Nb). We observe that the DT is significantly altered in these alloys by the application of a magnetic field. Specifically, the DT in InTl-24 at.% shows a decrease in the DT temperature with increasing magnetic field. Further investigations of AuZn were performed using an ultrasonic pulse-echo technique in magnetic fields up to 45 T. Quantum oscillations in the speed of the longitudinal sound waves propagating in the [110] direction indicated a strong acoustic de Haas-van Alphen-type effect and give information about part of the Fermi surface.
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We analyze generic sequences for which the geometrically linear energy [E_eta(u,chi):= eta^{-frac{2}{3}}int_{B_{0}(1)} left| e(u)- sum_{i=1}^3 chi_ie_iright|^2 d x+eta^frac{1}{3} sum_{i=1}^3 |Dchi_i|(B_{0}(1))] remains bounded in the limit $eta to
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