Asymetry of critical exponents in YBCO in the overdoped, optimally doped and underdoped regime. - Université Paris-Est-Créteil-Val-de-Marne Access content directly
Conference Papers Year : 1998

Asymetry of critical exponents in YBCO in the overdoped, optimally doped and underdoped regime.

Abstract

We analyze very precise specific heat data of μg mass detwinned single crystals of YBa_2Cu_3O_7-δ with a relative resolution δ C/C of 10-4 and δ T/T of 10-5. Oxygen doping varies in the range δ=3D0.99 (Tc=3D89.5K, overdoped) δ=3D0.95 (Tc=3D92.3K, optimal) and δ=3D0.87 (Tc=3D9= 1.2K, underdoped). A detailed analysis of the derivative of the specific heat data reveals a pronounced asymmetry of the critical exponent α. Above Tc α ^+=3D0.5± 0.2. Below Tc α ^-=3D-0.2± 0.3. This abnormal behavior cannot be explained within the framework of regular second order phase transitions. The asymmetry of the critical exponent is robust against a change of the phonon backround or a change in the choice of Tc and persists in the overdoped, underdoped and optimally doped regime.It suggests either the existence of a 1st order phase transition in zero field or the proximity to a multicritical point at optimal doping.
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hal-04136132 , version 1 (21-06-2023)

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Melissa Charalambous, B. Billon, O. Riou, P. Gandit, P. Lejay, et al.. Asymetry of critical exponents in YBCO in the overdoped, optimally doped and underdoped regime.. Annual March Meeting, American Physical Society, Mar 1998, Los angeles, United States. ⟨hal-04136132⟩
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