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[Display omitted] • XRD profiles revealed the Ruddlesden-popper phase in La 1.4-x Sm x Ca 1.6 Mn 2 O 7 (0.0 ≤ x ≤ 0.4) compounds. • With increasing the Sm-concentration the unit cell volume drastically reduced from 290.51 Å3 for x = 0.0 to 290.19 Å3, 289.76 Å3 and 289.22 Å3 for x = 0.1, 0.2 and 0.3 compounds respectively. • The planer (O(3)-Mn-O(3)) and out of plane (O(3)-Mn-O(1)) bond angles have consistently decreased from 87.87°, 78.88° for parent compound up to 85.41°, 73.58° for x = 0.3 composition respectively. • Maximum entropy change obtained for x = 0.0, 0.1, 0.2, 0.3 and 0.4 samples are 2.52 J/kgK, 4.61 J/kgK, 4.2 J/kgK, 2.48 J/kgK, 1.2 J/kgK respectively upon applying 2.5 T magnetic field. • The highest values of TEC enhanced from 4.04 J/kgK (x = 0.0) up to x = 8.5 J/kgK (x = 0.1) and 7.77 J/kgK (x = 0.2) with a Δ T H - C = 5 K. Evolution in the structural, magnetic and magnetocaloric (MCE) properties for a series of samarium (Sm) doped La 1.4-x Sm x Ca 1.6 Mn 2 O 7 (0.0 ≤ x ≤ 0.4) Ruddlesden-Popper manganites prepared by using the solid-state reaction method have been investigated. Structural refinement of XRD profiles established that the MnO 6 octahedral structural units were distorted upon Sm-substitution. The effect of Sm-concentration on the microstructure was also very well observed in terms of increased average grain size and absolute density. Discrepancy in MCE parameters by implementing the conventional isothermal curve method was appeared which was resolved with a separate calorimetric method. The isothermal entropy change was enhanced from 2.52 J/kgK for x = 0.0 sample up to 4.61 J/kgK and 4.2 J/kgK for x = 0.1 and x = 0.2 samples respectively. The temperature averaged entropy change (TEC) was also remarkably improved from 4.04 J/kgK up to 8.5 J/kgK and 7.77 J/kgK for the same compounds respectively. [ABSTRACT FROM AUTHOR]

We present the processing of functionally graded multi-material freeze-cast structures, i.e. structures with varying material properties but continuous and homogeneous microchannels. We demonstrate this for stepwise, continuous, highly viscous and gelation freezing to achieve freeze-cast structures of graded La 0.66 Ca 0.24 Sr 0.09 Mn 1.05 O 3 (LCSM9) and La 0.67 Ca 0.27 Sr 0.06 Mn 1.05 O 3 (LCSM6) ceramics. The two phases are successfully distinguished from one another by the addition of 10 wt% Ce 0.9 Gd 0.1 O 2 (CGO) to the LCSM6 phase. The relative Ce-content facilitates tracking of the LCSM6 phase using energy-dispersive X-ray (EDS) elemental analysis. Coupled with scanning electron microscopy, we show well-defined interfaces with continuous microchannels between the two LCSM phases in both green and sintered samples. By implementing constant freezing rates of −1.5 K/min a consistent freezing front velocity of ∼13 μm/s is maintained, and we found that a structural continuity can be maintained across the LCSM9–LCSM6/CGO interface, however, with varying pore morphology depending on the various freezing procedures. [ABSTRACT FROM AUTHOR]

Designing multicaloric single-phase materials with combined electro- and magnetocaloric effects is still at its initial stage and presents a number of challenges. One of the main challenges encountered so far is to reduce the excessive electrical conductivity, which leads to the appearance of Joule heating that might completely degrade the electrocaloric response. In this work, multicaloric Pb(Fe 0.5 Nb 0.5)O 3 material was successfully prepared exhibiting pronounced electrocaloric effect above room temperature and maximum magnetocaloric effect at cryogenic temperature. The conductivity was suppressed by controlling the sintering temperature. The ceramic sintered at 1000 °C exhibits maximum electrocaloric effective cooling of 0.88 °C at 28 °C and maximum magnetocaloric effect of 0.14 °C at −271 °C. The caloric properties can be further improved by doping Pb(Fe 0.5 Nb 0.5)O 3 with manganese. In comparison to the undoped sample, Pb(Fe 0.5 Nb 0.5)O 3 doped with 0.5 mol% of manganese exhibits three times higher maxima of electrocaloric effective cooling (2.47 °C at 80 °C) and magnetocaloric temperature change (0.44 °C at −271 °C). [ABSTRACT FROM AUTHOR]