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The inverse magnetocaloric effect (MCE) in Ni-Mn-based Heusler compounds occurs during the magnetostructural transition between low-temperature, low-magnetization martensite and hightemperature, high-magnetization austenite. In this study, we analyze the metamagnetic transformation of a Ni 49.8 Mn 35 In 15.2 compound by simultaneous adiabatic temperature change ΔT ad and strain Δl/l 0 measurements in pulsed magnetic fields up to 10 T. We observe a ΔT ad of -10 K and a Δl/l 0 of -0.22 % when the reverse martensitic transition is fully induced at a starting temperature of 285 K. By a variation of the magnetic field-sweep rates between 316 Ts -1 , 865 Ts -1 and 1850 Ts -1 , the transitional dynamics of the reverse martensitic transformation have been investigated. Our experiments reveal an apparent delay upon the end of the reverse martensitic transformation at field rates exceeding 865 Ts -1 which is related to the annihilation of retained martensite. As a consequence, the field hysteresis increases and higher fields are required to saturate the transition. In contrast, no time-dependent effects on the onset of the reverse martensitic transformation were observed in the studied field-sweep range. Our results demonstrate that kinetic effects in Heusler compounds strongly affect the magnetic cooling cycle, especially when utilising a multicaloric "exploiting-hysteresis cycle" where high magnetic fieldsweep rates are employed.

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Using our data on magnetic entropy change ΔSm, adiabatic temperature change ΔTad and heat capacity CH for La(FeCoSi)13 alloys, the upper limit of heat Qc transferred per cycle, and the lowest limit of consumed work Wc were established for magnetic refrigerators operating in Δμ0H=1.9 T . In order to estimate the cooling power, attributable to thermoelectric refrigerators with La(FeCoSi)13, thermal conductivity λ, resistivity ρ, and Seebeck coefficient α were measured and the maximal cooling power QL, the input power Pi, and coefficient of performance have been calculated. La(Fe,Si)13-based compounds are among the most promising magnetocaloric materials, they show a large magnetocaloric effect (MCE) and have been widely studied from perspective of fundamental research and practical applications.1,2 The magnetocaloric properties (adiabatic temperature change ΔTad and magnetic entropy change ΔSm) and the Curie temperature TC of La(Fe,Si)13 alloys can be widely adjusted by small additions of other elements like H or Co. The addition of Co also alters the nature of the magnetic phase transition from first to second order.3 Thermal conductivity λ and resistivity ρ are also required parameters for a comprehensive characterization of MCE materials. From other side, λ, ρ, and Seebeck coefficient α specify the efficiency of thermoelectric (TE) materials and by adding the Seebeck coefficient to the set of parameters suitable for MCE materials, we are also able to assess the utility of La(FeCoSi)13 compounds for application in TE modules. In addition to the material parameters ΔSm, ΔTad , CH, ρ, λ, and α, it is important to determine: (1) the amount of the heat Qc transferred per unit time, (2) the work Wc consumed by refrigerator per unit time, (3) the coefficient of performance (COP). Such universal parameters as Qc, Wc, and COP show the potential effectiveness of the refrigerator and refrigerant, irrespectively of the physical principle of cooling. This fact allows us to compare different refrigeration technologies. The objective of this work is the numerical determination of the maximal Qc, COP, and minimal Wc as a function of thermal span of magnetocaloric and thermoelectric refrigerators using La(FeCoSi)13 alloys. Sintered La(Fe1−xCox)Siy samples were produced by Vacuumschmelze GmbH. Detailed processing has been described previously.4 Samples of LaFe11.5Si1.5 and LaFe8Co5, both with the NaZn13-type structure, were prepared by technique described in Ref. 1 . CH was measured using a Quantum Design physical property measurement system (PPMS). Direct measurements of ΔTad were performed in a home-built experimental setup described in details elsewhere.5 Thermal conductivity measurements were performed using a steady-state method: the temperature gradient was first measured between two points in a rod sample, and then the λ was calculated based on Fourier's law taking account of the heat flux through a cross-section of the sample. The Seebeck coefficient α was measured straightforwardly. The temperature gradient was maintaine...

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Here, we report the structures and properties of biocatalysts based on glucose oxidase (GOx) macromolecules immobilized on the mesoporous zirconia surface with or without magnetic iron oxide nanoparticles (IONPs) in zirconia pores. Properties of these biocatalysts were studied in oxidation of Dglucose to D-gluconic acid at a wide range of pH and temperatures. We demonstrate that the calcination temperature (300, 400, or 600 °C) of zirconia determines its structure, with crystalline materials obtained at 400 and 600 °C. This, in turn, influences the catalytic behavior of immobilized GOx, which was tentatively assigned to the preservation of GOx conformation on the crystalline support surface. IONPs significantly enhance the biocatalyst activity due to synergy with the enzyme. At the same time, neither support porosity nor acidity/basicity shows correlations with the properties of this biocatalyst. The highest relative activity of 98% (of native GOx) at a pH 6−7 and temperature of 40−45 °C was achieved for the biocatalyst based on ZrO 2 calcined at 600 °C and containing IONPs. This process is green as it is characterized by a high atom economy due to the formation of a single product with high selectivity and conversion and minimization of waste due to magnetic separation of the catalyst from an aqueous solution. These and an exceptional stability of this catalyst in 10 consecutive reactions (7% relative activity loss) make it favorable for practical applications.