Direct measurements of the magnetic entropy change

Direct measurements of the magnetic entropy change.

An experimental device that can accurately measure the magnetic entropy change, Δs, as a function of temperature, T, and magnetic field, H, is presented. The magnetic field source is in this case a set of counter-rotating concentric Halbach-type magnets, which produce a highly homogeneous applied field with constant orientation. The field may be varied from 0 to 1.5 T in a continuous way. The t...

Direct measurement of the magnetic entropy change

Determination of the Magnetic Entropy Change from Magnetic Measurements: the Importance of the Measurement Protocol

The search for energy-efficient technologies for developing new refrigerator appliances has made the magnetocaloric effect a field of current scientific interest.1 The number of scientific publications on this topic is increasing exponentially in the recent years (Figure 1), which is proof of the high expectations that the scientific community is depositing on this field of research. Together w...

a synchronic and diachronic approach to the change route of address terms in the two recent centuries of persian language

terms of address as an important linguistics items provide valuable information about the interlocutors, their relationship and their circumstances. this study was done to investigate the change route of persian address terms in the two recent centuries including three historical periods of qajar, pahlavi and after the islamic revolution. data were extracted from a corpus consisting 24 novels w...

Direct calorimetric measurements of isothermal entropy change on single crystal W-type hexaferrites at the spin reorientation transition

We report on the magnetic field induced isothermal entropy change ∆s(Ha, T ) of W-type ferrite with CoZn substitution. Entropy measurement are performed by direct calorimetry. Single crystals of composition BaCo0.62Zn1.38Fe16O27, prepared by flux method, are measured at different fixed temperatures under applied field perpendicular and parallel to the c axis. At 296 K one deduces a value of K1 ...