Magnetic and Magnetocaloric Properties of K-Doped Pr0.5Sr0.5MnO3

We have studied the effect of potassium substitution on the magnetic and magnetocaloric properties of Pr0.5Sr0.5−xKxMnO3 (x = 0, 0.05, 0.1, 0.15, 0.2, and 0.3). X-ray diffraction results show an orthorhombic crystal structure formed at room temperature for x ≤ 0.2. The maximum entropy change (|ΔSM|max) of the samples gradually increases from 1.15 (x = 0) to 3.37 J kg−1 K−1 (x = 0.3) in a magnetic field change of 15 kOe with increasing concentration of potassium. The Curie temperatures (TC) are found to be 265, 285, 295, 300, 295, and 220 K for x = 0, 0.05, 0.1, 0.15, 0.2, and 0.3, respectively. The temperature range of the phase transition becomes wider, the relative cooling power (RCP) gradually increases with the content of potassium, and the largest RCP is achieved to be 63.5 J kg−1 for x = 0.3, which makes it as a desirable material for the room temperature magnetic refrigeration.