  The inverse magnetocaloric effect (MCE) in Ni-Mn-based Heusler compounds
occurs during the magnetostructural transition between low-temperature,
low-magnetization martensite and high-temperature, 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 and strain measurements in pulsed magnetic fields up to 10 T. We observe
an adiabatic temperature change of -10 K and a strain 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
field-sweep rates are employed.
