The magnetocaloric effect (MCE) in the magnetic terbium dihydride TbH1.92, TbH2.03 and TbH2.09 samples has been evaluated from the heat capacity C-p(T) measurements under-zero field and 9 T. The MCE phenomena in the vicinity of the magnetic phase transitions in terms of the magnetic-entropy change, Delta S-M, and adiabatic temperature change, Delta T-ad, are reported. The magnetic-entropy changes, -Delta S-M = (S-H - S-O) exhibit complex temperature dependence. They have negative values below the magnetic transition temperature T-max (the inverse magnetocaloric effect) and change sign at higher temperatures going to the normal magnetocaloric effect. The absolute vertical bar Delta S-M vertical bar I maximum values are 1.55 J/mol K (9.62 J/kg K) for TbH1.92, 2.0 J/mol K (12.42 J/kg K) for TbH2.03 and 1.50 J/mol K (9.31 J/kg K) for TbH2.09 at temperatures equal to 13 K. 12.5 K and 11.5 K, respectively. The Tb-H system provides magnetic refrigerants which induce adiabatic cooling of about Delta T-ad approximate to 2 K during the magnetization process with a field of 9T in the temperature range of 10-15 K.
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