Thermal properties of $$^{172}\mathrm{Yb}$$ and $$^{162}\mathrm{Dy}$$ isotopes in the back-shifted Fermi gas model with temperature-dependent pairing energy

Abstract

Thermodynamic properties of $$^{172}\mathrm{Yb}$$ and $$^{162}\mathrm{Dy}$$ isotopes are investigated using the back-shifted Fermi-gas (BSFG) model with the energy-dependent level density parameter and the temperature-dependent pairing energy. The temperature dependency of pairing energy is applied using the mean order parameter of the exact Ginzburg–Landau (EGL) theory. The level density, entropy, temperature and heat capacity of $$^{172}\mathrm{Yb}$$ and $$^{162}\mathrm{Dy}$$ isotopes are calculated using these approaches and the results are compared with each other as well as with experimental data to examine the validity of these models. The results obtained by the present study indicate that the BSFG model with the temperature-dependent pairing energy is in better agreement with the experimental data, compared to the BSFG model with the energy-dependent level density parameter, for $$^{172}\mathrm{Yb}$$ and $$^{162}\mathrm{Dy}$$ isotopes.