Correlation Between Magnetocaloric Effect and Crystal Growth in La\(_{1.4}\)Ca\(_{1.6}\)Mn\(_2\)O\(_7\)

We present systematic studies of calcium-doped lanthanum manganite La \(_{1.4}\) $_{1.4}^{}$ Ca \(_{1.6}\) $_{1.6}^{}$ Mn \(_2\) $_2^{}$ O \(_7\) $_7^{}$ with differing preparation conditions, focusing on the ferromagnetic to paramagnetic transition. Particle size increased with sintering temperature, but the lattice constant remained unchanged. The discontinuity in heat capacity at \(T_\textrm{C}= 270\) $T_{\text{C}}=270$ K showed a tendency to increase with rising heat treatment temperature. For the furnace-cooled sample at a heat treatment temperature of 1450 \(^{\circ }\) $_{}^{\circ }$ C, the maximum magnetic entropy change was \(\Delta S_\textrm{max}= 6.0\) $\mathrm{\Delta }{S}_{\text{max}}=6.0$   J/kg  K at 255 K. However, for the quench-cooled sample at the same sintering temperature of 1450 \(^{\circ }\) $_{}^{\circ }$ C, despite the grain size being almost identical, \(\Delta S_\textrm{max}\) $\mathrm{\Delta }{S}_{\text{max}}$ was only two-thirds of this value. This suggests that factors other than particle size and porosity also influence magnetic scattering.