A5056649900- Magnetic and transport properties of perovskites and related materials
- Shape Memory Alloy Transformations
- Rare-earth and actinide compounds
- Heusler alloys: electronic and magnetic properties
- Magnetic Properties of Alloys
- Thermal Expansion and Ionic Conductivity
- Advanced Condensed Matter Physics
- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Phase Equilibria and Thermodynamics
- Thermodynamic properties of mixtures
- Magnetic Properties and Applications
- Inorganic Chemistry and Materials
- Chemical Thermodynamics and Molecular Structure
- Iron-based superconductors research
- Ferroelectric and Piezoelectric Materials
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Nuclear Physics and Applications
- Multiferroics and related materials
- High Entropy Alloys Studies
- Superconductivity in MgB2 and Alloys
Bielefeld University
2023-2025
Variable Energy Cyclotron Centre
2010-2024
Homi Bhabha National Institute
2023-2024
Leibniz Institute for Solid State and Materials Research
2021
Louisiana State University
2013-2019
Southern Illinois University Carbondale
2011-2018
Shyam Shah Medical College
2012-2015
Saha Institute of Nuclear Physics
2006-2013
University of South Florida
2013
University of Nebraska–Lincoln
2013
Giant magnetocaloric effect has been observed in ErRu2Si2, which is associated with field-induced metamagnetic transition from antiferromagnetic to ferromagnetic state. The maximum values of magnetic entropy change (−ΔSMmax) and adiabatic temperature (ΔTadmax) for a field 7T are evaluated be 19.3J∕kgK 15.9K, respectively, around 5.5K within the range 4–25K. value ΔTadmax even larger than other potential refrigerant materials reported same also comparable room giant exhibiting first-order paramagnetic
Magnetic and structural transitions were found to coincide by substituting Cu for Mn in Mn1−xCuxCoGe, leading a giant magnetocaloric effects associated with the first-order magnetostructural phase transition from ferromagnetic paramagnetic state. Maximum magnetic entropy changes of −ΔSM = 52.5 53.3 J/kg K field change ΔH 5 T have been observed at 302 316 K, x 0.080 0.085, respectively. The tunable temperatures through subtle variations composition make this system promising room-temperature...
By means of alloying appropriate amounts MnNiSi and MnFeGe, materials are found that undergo a paramagnetic to ferromagnetic transition close room temperature, accompanied by huge volume change. Thanks this change, application moderate pressures leads remarkable enhancement the magnetocaloric response. Work like may open new opportunities in development solid-state magnetic refrigeration devices.
The thermomagnetic and magnetocaloric properties of the MnNiGe1−xAlx system have been investigated by magnetization differential scanning calorimetry (DSC) measurements. presence first-order magnetostructural transitions (MSTs) from hexagonal ferromagnetic to orthorhombic antiferromagnetic phases has detected for x = 0.085 0.09 at 193 K 186 K, respectively. values latent heat (L 6.6 J/g) corresponding total entropy changes (ΔST 35 J/kg K) evaluated MST (x 0.09) DSC magnetic change (ΔSM 17.6...
(MnNiSi)1−x(FeCoGe)x undergoes a magnetostructural phase transition near room temperature that is acutely sensitive to applied hydrostatic pressure, which presents as marked shift in the martensitic (TM) by about –7.5 K/kbar. The can therefore be induced pressure or magnetic field. barocaloric and magnetocaloric effects were measured across TM (for sample with x = 0.38), corresponding entropy changes +74 J/kg K (P 2.7 kbar) –58 (μ0 H 5 T), respectively. It was observed change increases...
A comprehensive study of the temperature ($T$) and magnetic field ($H$) dependence entropy change ($\ensuremath{\Delta}{S}_{M}$) for different materials exhibiting inverse magnetocaloric effect (IMCE) is reported. We show that $\ensuremath{\Delta}{S}_{M}$ follows a power-law $H$ ($\ensuremath{\Delta}{S}_{M}$ \ensuremath{\sim} ${H}^{n}$; $n$ an exponent) these compounds. In contrast to conventional (CMCE), independent $T$ in case IMCE. As result, universal master curve can be constructed...
The study of magnetocaloric effect has been performed on polycrystalline Ho5Pd2 compound, which undergoes magnetic field-induced first order metamagnetic transition from antiferromagnetic to ferromagnetic state below temperature. A large entropy change associated with the observed over a wide temperature range. evaluated value relative cooling power is 6.32J∕cm3 for field 5T, even larger than that reported best known refrigerant materials irrespective
Room temperature x-ray diffraction, dc magnetization, and ac susceptibility measurements have been performed on a series of Mn rich Ni50Mn37-xCrxSb13 Ni50+xMn37-xSb13 Heusler alloys. Depending the value x, room crystal structures samples are either L21 cubic or orthorhombic. It is commonly accepted idea that martensitic transition temperatures in Ni-Mn-Z (Z = Ga, In, Sb, Sn) based alloys decrease (increase) with decreasing (increasing) valence electron concentration, e/a. However, present...
The isostructural alloying of two compounds with different magnetic and thermo-structural properties has resulted in a new system, (MnNiSi)1−x(FeCoGe)x, that exhibits large magnetocaloric effects acute sensitivity to both compositional variation applied hydrostatic pressure. maximum isothermal entropy change reaches value −ΔSmax = 143.7 J/kg K for field ΔB 5 T at atmospheric first-order magnetostructural transition responsible the shifts lower temperature pressure (∼−10 K/kbar) but maintains −ΔSmax.
The nature of martensitic phase transitions and its modification as a function composition application magnetic field have been studied in detail for Ni40Co10Mn40Sn10-xGax (x=0, 0.3, 0.4 0.5). transition temperature (TM) increases with increasing x. kinetic arrest (KA) the austenitic has observed x=0 which disappeared x>0.3. KA results decrease change magnetization (ΔM) across TM. However, isothermal entropy ΔS varies almost linearly [dTM/d(μ0H)]−1 (field-induced shift TM) irrespective...
Nanocrystalline Pr0.65(Ca0.7Sr0.3)MnO3 show large magnetocaloric effect at their charge order transition temperature (TCO) as well the which spontaneous destabilization of ordered state occurs (TM). In comparison to polycrystalline bulk form, TM’s are substantially enhanced in cases nanocrystalline samples, whereas TCO’s remain almost unchanged. Although there is no clear signature dependence magnetic susceptibility and resistivity for sample with lower particle size, a maxima due visible...
Magnetotransport and magnetocaloric properties of polycrystalline Pr0.65(Ca0.7Sr0.3)MnO3 have been studied. Large low field magnetoresistance (∼100% at 75K for 1T field) with high magnetic sensitivity (∼5000%T−1) has observed due to the melting charge ordered state. The system also shows large effect ∼215 90K. entropy change is ∼8 5.5J∕kgK, respectively, around these temperatures a from 0to7T. Such huge along exhibited by material interesting application point view.
Some recent experimental studies show the invisibility of antiferromagnetic transition in cases manganites when their particle size is reduced to nanometer scale. In complete contrast these cases, we have observed signature magnetocaloric properties nanocrystalline La0.125Ca0.875MnO3 average sizes 70 and 60 nm similar its polycrystalline bulk form. The system exhibits inverse effect forms. An extra ferromagnetic phase stabilized at low temperature for sample with ∼60 nm.
The magnetocaloric and thermomagnetic properties of the MnNiGe1−xAlx system have been studied by temperature-dependent x-ray diffraction, differential scanning calorimetry (DSC), magnetization measurements. partial substitution Al for Ge in results a first order magnetostructural transition (MST) from hexagonal ferromagnetic to an orthorhombic antiferromagnetic phase at 186 K (for x = 0.09). A large magnetic entropy change ΔSM −17.6 J/kg ΔH 5 T was observed vicinity TM 0.09. value is...
We report the universal behavior of inverse magnetocaloric effect (IMCE) in antiferromagnetic materials. In contrast to conventional often observed ferromagnetic systems, a phenomenological master curve can be constructed describe temperature dependence magnetic entropy change for IMCE without rescaling axis. The proposed method allows extrapolating an material, which would imperative judge its suitability actual refrigeration devices.
A series of Mn rich Ni50Mn37−xCrxSb13 Heusler alloys have been investigated by dc magnetization and electrical resistivity measurements. Due to the weakening Ni-Mn hybridization, martensitic transition shifts lower temperatures with increasing Cr concentration, while saturation at 5 K increases. The magnetoresistance exchange bias properties are dramatically suppressed concentration. observed behaviors suggest that substitution for in not only destabilizes phase but also enhances...
We report the electronic structure, synthesis, and measurements of magnetic, transport, thermal properties polycrystalline noncentrosymmetric compound ${\mathrm{Re}}_{6}\mathrm{Zr}$. observed a bulk superconducting transition at temperature ${T}_{c}\ensuremath{\sim}6.7$ K, measured resistivity, heat capacity, conductivity, London penetration depth below transition, as well performed doping pressure studies. From these we extracted critical field parameters Our indicate relatively weak to...
The magnetic and structural transitions can be controlled to coincide by partial substitution of Zn for Co in MnCo1−xZnxGe, leading a large magnetocaloric effects over wide temperature range. magnetostructural transition from paramagnetic ferromagnetic state results entropy changes (−ΔSM) 26 J/kg K at 327 ΔH = 5 T the case x 0.045. Interestingly, structurally driven first-order phase between two high magnetization states as observed 0.05 0.06 also lead values −ΔSM 31.4 20.6 281 209 K,...
MnNiSi-based alloys and isostructural systems have traditionally demonstrated impressive magnetocaloric properties near room temperature associated with a highly tunable first-order magnetostructural transition that involves large latent heat. However, these materials are limited by small field-sensitivity of the transition, preventing significant reversible effects usable for cooling applications. Instead, concomitant volume changes prompt high pressure-sensitivity, therefore, promise...
Abstract An innovative residual analysis based method is proposed for pulse shape discrimination and segregation of neutron gamma pulses liquid scintillator-based detector (BC501A). This study develops a simple efficient algorithm neutrons gammas from mixed environment then segregate the into two label datasets. involves analyzing residuals between measured reference in normalized scale. By examining these residuals, users can identify characteristics unique to each type radiation. The...