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arXiv · 0910.3567

Development of the critical exponent at the antiferromagnetic phase transition of YbRh2Si2 under chemical pressure

C. Krellner·C. Klingner·C. Geibel·F. Steglich
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Abstract

We present specific-heat measurements in the vicinity of the antiferromagnetic phase transition on single crystals of the alloy Yb(Rh_{1-x}Co_x)2Si2 for x<= 0.38. This study was motivated by the violation of critical universality in the undoped YbRh2Si2 (Krellner et al., Phys. Rev. Lett. 102, 196402) where we have found a large critical exponent a=0.38. For Co-doped samples we observe a drastic change of the critical fluctuations resulting in a negative a, explainable within the universality classes of phase transitions. The development of a under chemical pressure gives strong indication that the violation of critical universality in YbRh2Si2 is due to the nearby quantum critical point.

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C. Krellner, C. Klingner, C. Geibel, F. Steglich. 2009-10-19. Development of the critical exponent at the antiferromagnetic phase transition of YbRh2Si2 under chemical pressure. https://doi.org/10.1002/pssb.200983014

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