Growth, structure, and magnetocaloric effect of Ce2X3(NO3)12·24H2O (X=Cu, Co) crystals

Single crystals of Ce 2 X 3 (NO 3 ) 12 ·24H 2 O (X=Cu, Co, CXN) were successfully synthesized, all crystallizing in the trigonal space group R ¯ 3 $\overline{R}3$ . Under a magnetic field variation of 0-9 T at 2 K, Ce 2 Cu 3 (NO 3 ) 12 ·24H 2 O and Ce 2 Co 3 (NO 3 ) 12 ·24H 2 O exhibit large magnetic entropy changes of 15.18 J·kg -1 ·K -1 and 16.19 J·kg -1 ·K -1 , respectively. Notably, the magnetic entropy changes of these novel crystals significantly exceed that of Ce 2 Mg 3 (NO 3 ) 12 ·24H 2 O (CMN), which is only 6.33 J·kg -1 ·K -1 under identical conditions. Meanwhile, the refrigerant capacity (RC), constrained-range equivalent refrigerant capacity product (RCP) and temperature-averaged entropy change (TEC) of CXN are also comprehensively superior to those of CMN. These performances suggest that CXN are promising candidates for ultra-low temperature magnetic refrigeration applications.