The adiabatic temperature change (ΔT) during the magnetization and demagnetization processes of bulk gadolinium is directly measured for several applied magnetic fields in range 285 K to 305 K. During process, ΔT measurements display same maximum each field when plotted against initial (Ti). However, varies field. This discrepancy between appears inconsistent with reversibility magnetocaloric effect. A new approach undertaken highlight effect by plotting average (Tavg) instead Ti. value Tavg...

A systematic study of the magnetocaloric effect a Ni51Mn33.4In15.6 Heusler alloy converted to nanoparticles via high energy ball-milling technique in temperature range 270 310 K has been performed. The properties particles were characterized by x-ray diffraction, electron microscopy, and magnetometer techniques. Isothermal magnetic field variation magnetization exhibits hysteresis bulk across martensitic transition which significantly lessened nanoparticles. effects nanoparticle samples...

The magnetocaloric temperature change (ΔT <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Temp</sub> ) is an important factor in the performance evaluation of material's effect (MCE), which has been attracting significant interest due to its application energy efficient near-room magnetic refrigeration technology with environmentally desirable characteristics. A novel test system fully controlled field, temperature, and time capabilities...

The NiMnInSi Heusler alloy family is analyzed, and a self-similarity based method used to analyze the first-order transition of Ni-Mn alloys. This appropriate determine magnetic characteristics Magnetocaloric Effect providing that there sufficient separation in their phase temperatures. A temperature scaling methodology model cluster compositions mixed-state regions where two stable states co-exist. various descriptions classifications these transitions, however, are not critical this analysis.

A systematic study of the size effect on magnetic and structural properties a Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">51</sub> Mn xmlns:xlink="http://www.w3.org/1999/xlink">33.4</sub> In xmlns:xlink="http://www.w3.org/1999/xlink">15.6</sub> Heusler alloy converted to nanoparticles has been performed. We present new data explain enhanced nanostructured synthesized through high-energy ball-milling technique. The particles were...

A systematic study of the size effect on magnetic and structural properties Y2Fe17 nanoparticles has been performed. We present new data to explain enhanced nanostructured yttrium-iron alloy synthesized through alkalide reduction chemical synthesis. The particles were characterized by x-ray diffraction, electron microscopy, magnetometer techniques. As is reduced, there an increase in magnetization per unit applied field, a decrease coercivity substantial hysteresis.

The latent heat linked with the first-order transformation of a NiMnIn Heusler alloy has been studied through direct measurements adiabatic temperature change, ΔTad, during magnetization process. experimental procedure used guarantees independent data points and negates any contribution hysteretic losses to magnetocaloric effect. Thus, differences between magnitudes ΔTad initial change directions from low-to-high high-to-low are solely attributed exchange, which accompanies irreversible...

A model for the magnetostriction of high-strength steels under uniaxial compressive stresses is presented to simulate experimental measurements. previous Preisach-type modified Villari reversal phenomenon. The can also account crystallographic anisotropy which arises from stress magnitude as well machining process sample. net axial sample modeled by a Preisach-type, two-component model. first component corresponds steep rise in initial stage followed rotation magnetic domains direction...

To make nanoparticles useful to fit various applications, the fundamental understanding of their magnetic and structural behavior is essential. A systematic in-depth study effect field, temperature, size on critical points, properties chemically synthesized Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Fe xmlns:xlink="http://www.w3.org/1999/xlink">17</sub> have been performed. The blocking temperature varies with change in applied...

The metastability of the nonstoichiometric Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">51</sub> Mn xmlns:xlink="http://www.w3.org/1999/xlink">33.4</sub> In xmlns:xlink="http://www.w3.org/1999/xlink">15.6</sub> Heusler alloy in first-order transition region is studied using direct adiabatic temperature change (ΔT xmlns:xlink="http://www.w3.org/1999/xlink">ad</sub> ) measurements for heating and cooling magnetization processes. During...

In this work we are reporting on the development of a novel Surface Acoustic Wave (SAW) device based MEMS technology for drug delivery in treatment ocular diseases. The miniaturized SAW will be placed eye surface to allow non-invasive long-term application programmed timeline and electronic control regiment. This method is expected lead better clinical outcomes various diseases, improved patient compliance with therapy. can precise amounts drugs at predetermined times over several months,...

Heusler alloys feature both conventional and inverse magnetocaloric effects near room temperature as they undergo two different transitions. In this paper, new data are presented analyzed a mechanism to explain the complex hysteretic behavior of Ni48Co2Mn35In13Ga2 alloy is developed. This explains isothermal loops temperature. The various descriptions classifications these transitions, however, not critical analysis.

A new experimental test bed has been designed, built, and tested to evaluate the effect of system’s parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as refrigerant, silicon oil heat transfer medium, magnetic field 1.3 T cycled. This study focuses methodology single stage AMR operation conditions get high temperature span Herein, main objective is not report absolute maximum attainable seen in an system, but rather find optimal...

In this work the magnetocaloric effect (MCE) and hysteresis losses of Ni45Co5Mn(37-x)In(13+x) alloy (x= 0, 0.4) are studied. Also we propose a new approach in calculating average entropy change to eliminate overestimation magnetic calculation using Maxwell’s relations which is commonly seen indirect MCE literature. The attributes magnetostructural coupling have an important role behavior these magnetofunctional alloys. This exhibits that strong can be achieved over wide temperature range...

The adiabatic temperature change (ΔTad) during the magnetization process of polycrystalline gadolinium and Ni51Mn33.4In15.6 Heusler alloy is directly measured near Curie temperature. cooling factor (CF) introduced as area under curve versus ambient CF provides more representative measure performance in operational range. Selecting different abscissas qualitatively changes interpretation a magnetocaloric material. In particular, plotting ΔTad initial gives measurably compared to that given by average

The adiabatic temperature change (ΔT) during the magnetization and demagnetization processes of bulk gadolinium is directly measured for several applied magnetic fields in range 285 K to 305 K. In low fields, measurements ΔT display two maxima at 293.8 291.5 with an inflection point between 289 293 height second peak more pronounced diminishes high fields. occurrence a maximum indicative complex spin dynamics Gd related presence metastable states near Curie temperature.

In this work, we present the detailed results of magnetic, structural, and magnetocaloric measurements in Ni-Mn-In-based Heusler alloys, namely, Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">51</sub> Mn xmlns:xlink="http://www.w3.org/1999/xlink">32.8</sub> xmlns:xlink="http://www.w3.org/1999/xlink">16.2</sub> , xmlns:xlink="http://www.w3.org/1999/xlink">50.2</sub> xmlns:xlink="http://www.w3.org/1999/xlink">33.6</sub>...

The rate-independent stabilization of magnetic states with iterations in a Heusler alloy has been studied. direct measurement the adiabatic temperature change, ΔTad, Ni51Mn33.4In15.6 near magnetostructural phase transition is presented. change at given within range history dependent and varies considerably iteration count field cycle. data show from low magnetization state to high during (L–H) direction (H–L) require several cycles stabilize ΔTad measurement, similar accommodation phenomenon...

A study of dynamic and reversible voltage-controlled magnetization switching in ferromagnetic Co/Pt thin film with perpendicular magnetic anisotropy at room temperature is presented. The change the properties system observed a relatively thick 15 nm. surface charge induced by formation electrochemical double layer between metallic non-aqueous lithium LiClO4 electrolyte to manipulate magnetism. occurred application an external electric field. As negative voltage was increased, coercivity...

A new experimental test bed has been designed, built, and tested to evaluate the effect of systems parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as refrigerant, silicon oil heat transfer medium, magnetic field 1.3 T cycled. This study focuses methodology single stage AMR operation conditions get higher temperature span Herein, main objective is not report absolute maximum attainable seen in an system, but rather find optimal...