ACTA

Anomalies of Heat Capacity and Phase Transitions in Tm_{1 - x}Yb_xB₁₂

N.E. Sluchanko^a, A.N. Azarevich^a, A.V. Bogach^a, V.V. Glushkov^a, S.V. Demishev^a, S.Yu. Gavrilkin^b, N.Yu. Shitsevalova^c, V.B. Fillipov^c, S. Gabani^d and K. Flachbart^d
^aA.M. Prokhorov General Physics Institute of RAS, 38, Vavilov Str., Moscow, 119991, Russia
^bP.N. Lebedev Physical Institute of RAS, 53, Leniskii prospect, Moscow, 119991, Russia
^cInstitute for Problems of Materials Science of UAS, 3, Krzhyzhanovsky Str., 03680 Kiev, Ukraine
^dCentre of Low Temperature Physics, IEP SAS and IPS FS UPJS, 04001 Košice, Slovakia

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In the system Tm_{1 - x}Yb_xB₁₂ the specific heat has been studied in a wide range of Yb-concentration in the vicinity of the quantum critical point x_C ≈ 0.3. The results were obtained on high quality single crystalline samples of Tm_0.7Yb_0.3B₁₂ compound placed near quantum critical point, both for antiferromagnetic metals (x < x_C) as well as for paramagnetic insulators (x > x_C) within a wide temperature range of 1.9-300 K in magnetic field up to 9 T. The temperature dependence of the magnetic contribution to specific heat for Tm_0.74Yb_0.26B₁₂ shows a logarithmic divergence of the form: C_mag/T∿-lnT at T<4 K, which may be attributed to the quantum critical regime, and it is suppressed by strong external magnetic field. The Schottky anomaly of the magnetic contribution to specific heat in Tm_{1 - x}Yb_xB₁₂ has been established and analyzed in detail.

DOI: 10.12693/APhysPolA.118.929
PACS numbers: 75.40.-s