Investigation of magneto-volume effect of DyCo${}_2$ compound under isothermal and adiabatic mode of magnetic field change

The new unic measurement setup for the simultaneous measurement of magneto-thermal and magnetostrictive properties of magnetic materials was made. A complex investigation of the magnetocaloric and magneto-volume effects of the DyCo$_2$ compound with the first order metamagnetic transition were carried out. It was found that the magnitude of the magneto-volume effect in the DyCo${}_2$ compound under the adiabatic magnetic field change is 20% less than under isothermal conditions. This effect is explained by the fact that during the adiabatic magnetization, the temperature of the sample changes due to magnetocaloric effect, which leads to the sample goes from the demagnetized state to a magnetized one along a way that does not correspond to the maximum effect. This behavior of the material should occur in the real magnetic solid-state heat pump designing.