Browsing by Author "Blázquez Gámez, Javier Sebastián"
Now showing items 1-20 of 56
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A constant magnetocaloric response in FeMoCuB amorphous alloys with different FeB ratios [Article]
(AIP Publishing, 2007-05-04)The magnetocaloric effect of Fe91−xMo8Cu1Bx (x = 15 , 17 , 20) amorphous alloys has been studied. The temperature of the peak of magnetic entropy change can be tuned by altering the Fe / B ratio in pk pk the alloy, without ...
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A Finemet-type alloy as a low-cost candidate for high-temperature magnetic refrigeration [Article]
(AIP Publishing, 2006)The refrigerant capacity RC of Fe68.5Mo5Si13.5B9Cu1Nb3 alloy is studied. For the amorphous sample, RC=63 J kg−1 for an optimal reversible cycle with cold and hot ends at 328 K and 520 K, respectively, for a maximum ...
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A procedure to extract the magnetocaloric parameters of the single phases from experimental data of a multiphase system. [Article]
(AIP Publishing, 2014)In this work, we propose a method to extract the individual parameters that describe the field dependence of magnetic entropy change of each phase in a multiphase system. This method makes use of the scaling laws of the ...
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A unified approach to describe the thermal and magnetic hysteresis in Heusler alloys [Article]
(American Institute of Physics Publising LLC, 2016)Different excitations, like temperature, magnetic field, or pressure, can drive a martensitic transition in Heusler alloys. Coupled phenomena in these materials lead to interesting magnetocaloric and barocaloric effects ...
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Amorphization and evolution of magnetic properties during mechanical alloying of Co62Nb6Zr2B30: dependence on starting boron microstructure [Article]
(Elsevier, 2014)Co62Nb6Zr2B30 composition was mechanically alloyed using three different types of boron powders in the starting mixture: crystalline β-B, commercial amorphous B and optimized amorphous B via ball milling. Using optimized ...
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Analysis of nanocrystallization kinetics and crystal size distribution under limited growth approach [Article]
(Elsevier, 2012)Two different simulation approaches have been used to describe nanocrystallization processes: a limited growth approach, which is an extension from instantaneous growth approximation, and an average soft impingement ...
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Ball milling nanocrystallization of arc-melted and melt-spun Fe78Co5Nb3Zr3B5Ge5Cu1 alloy: microstructure and magnetic properties [Article]
(Taylor & Francis, 2006)The viability of developing a nanocrystalline microstructure for the Fe78Co5Nb3 Zr3B5Ge5Cu1 composition using a planetary ball mill was studied. Two starting samples were chosen: an arc-melted ingot and a partially ...
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Cellular automata simulations on nanocrystallization processes: From instantaneous growth approximation to limited growth [Article]
(Elsevier, 2011-07)Cellular automata simulations have been performed to simulate the crystallization process under a limited growth approximation. This approximation resembles several characteristics exhibited by nanocrystalline microstructures ...
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Comparison of equivalent ball milling processes on Fe70Zr30 and Fe70Nb30 [Article]
(Elsevier, 2012)Dynamical analysis of the movement of a single ball in a planetary ball mill yields a cubic law with the frequency of the mill for the power released during the process. This fact has been explored for two binary compositions ...
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Correlation between microstructure and temperature dependence of magnetic properties in Fe 60 Co 18 ( Nb , Zr ) 6 B 15 Cu 1 alloy series [Article]
(AIP Publishing, 2009-05-14)Temperature dependence of magnetic properties of nanocrystalline Fe60Co18Cu1B15Nb6−xZrx (x =0, 3, 6) alloys has been studied at different stages of devitrification. Transmission electron microscopy shows nanocrystals of ...
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Cristalización de aleaciones FeCoNbB(Cu) : Microestructura y propiedades magnéticas [PhD Thesis]
(2002) -
Crystallization kinetics and soft magnetic properties in metalloid-free (Fe, Co)90Zr10 amorphous and nanocrystalline alloys [Article]
(Elsevier, 2014)Microstructure and magnetic properties of metalloid-free (Fe100- xCox)90Zr10 amorphous and nanocrystalline alloys were characterized. Devitrification of these amorphous alloys occurs in two overlapped transformations leading ...
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Detection of the onset of nanocrystallization by calorimetric and magnetic measurements [Article]
(AIP Publishing, 2005-01-24)It is generally accepted that measurements of the magnetic properties are more sensitive than measurements of the enthalpy changes in the detection of the onset of crystallization of ferromagnetic phases emerging from a ...
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Distribution of transition temperatures in magnetic transformations: Sources, effects and procedures to extract information from experimental data [Article]
(Multidisciplinary Digital Publishing Institute (MDPI), 2020)The presence of a distribution of transition temperatures (DTT) is ubiquitous in materials science. It is common to ascribe deviations from theoretical pure-phase behavior to this fact. To adapt the different pure phase ...
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Effect of partial substitution of Ge for B on the high temperature response of soft magnetic nanocrystalline alloys [Article]
(Elsevier, 2005)The effect of partial substitution of Ge for B in Fe78Co5Zr6B10Cu1 alloy on the microstructure, crystallization process and magnetic properties of the amorphous and nanocrystalline alloys was studied. Special attention was ...
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Effects of high temperature treatments in air and argon on the magnetic properties of HITPERM alloys [Article]
(Elsevier, 2006)The oxidation behavior of FeCo(NbZr)B(Cu) alloy series was studied. After heating up to 1073 K, an oxide layer View the MathML source∼1μm thick with a two-layer structure can be identified previous to a sharp interface ...
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Enhanced cryogenic magnetocaloric effect in Eu8Ga16Ge30 clathrate nanocrystals [Article]
(AIP Publishing, 2015)We observe an enhanced magnetic entropy change ( D S M ) at cryogenic temperatures (T < 20 K) in Eu 8 Ga 16 Ge 30 clathrate (type-I) nanocrystals prepared by a ball milling method. With reduction in the ...
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Evolution of Fe environments in mechanically alloyed Fe–Nb–(B) compositions [Article]
(Elsevier, 2014)Nanocrystalline alloys of nominal composition Fe85Nb5B10 were produced by mechanical alloying from a mixture of elemental powders. Two commercial boron structures were used: amorphous and crystalline. In addition, a third ...
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Extracting the composition of nanocrystals of mechanically alloyed systems using Mössbauer spectroscopy [Article]
(Elsevier, 2014)Determining the composition at the nanoscale generally requires the use of experimental techniques such as 3D atom probe or nanoanalysis, which have limited availability, involve high economic cost and, moreover, imply ...
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Field dependence of the magnetocaloric effect in materials with a second order phase transition: A master curve for the magnetic entropy change [Article]
(AIP Publishing, 2006)The field dependence of the magnetic entropy change can be expressed as SM Hn. For soft magnetic amorphous alloys n=1 well below the Curie temperature TC , n=2 in the paramagnetic range, and n 0.75 for T=TC. The first ...