Abstract:In an effort to improve the magnetocaloric effects of the NaZn13-type La0.8Ce0.2Fe11.4Si1.6 compound, the effect of boron doping on the magnetic properties and magnetocaloric properties has been investigated. The magnetic entropy change (ΔSM) for the La0.8Ce0.2Fe11.4Si1.6 compound, obtained for a field change of 0–5 T using the Maxwell relation exhibits a spike and appears to be overestimated and is thus corrected by using the Clausius-Clapeyron equation (CC). The ΔSM determined from the CC equation is estimat… Show more
“…Noteworthily, the RC eff of the present Co6 alloy reaches 223 J/kg, which is significantly larger than those of the stoichiometric Ni-Mn-based alloys 18,45,76,77,79,81–84 and is comparable to those of some Co-doped Mn-rich Ni-Mn-based compounds 1,63,78–80,83 . Besides, the achieved RC eff is also comparable to those rare-earth containing La(FeSi) 13 -based 72,73 and Gd 5 (SiGe) 4 -based 74,75 compounds. Of note is that the working temperature of the present alloy is slightly above 300 K, which is very encouraging for room-temperature magnetic refrigeration applications.Figure 8Effective magnetic refrigeration capacity RC eff and working temperature span under a magnetic field of 5.0 T for the present Co6 alloy and some most studied magnetocaloric materials, such as La(FeSi) 13 -based 72,73 , Gd 5 (SiGe) 4 -based 74,75 , NiMn-based 1,18,45,63,76–84 compounds.…”
Section: Resultsmentioning
confidence: 54%
“…Besides, the achieved RC eff is also comparable to those rare-earth containing La(FeSi) 13 -based 72,73 and Gd 5 (SiGe) 4 -based 74,75 compounds. Of note is that the working temperature of the present alloy is slightly above 300 K, which is very encouraging for room-temperature magnetic refrigeration applications.Figure 8Effective magnetic refrigeration capacity RC eff and working temperature span under a magnetic field of 5.0 T for the present Co6 alloy and some most studied magnetocaloric materials, such as La(FeSi) 13 -based 72,73 , Gd 5 (SiGe) 4 -based 74,75 , NiMn-based 1,18,45,63,76–84 compounds. These alloys were selected because their magnetocaloric effects (MCE) are all related to the first-order martensite transformation and are tested around the magnetostructural transition temperatures.…”
High magnetocaloric refrigeration performance requires large magnetic entropy change ΔSM and broad working temperature span ΔTFWHM. A fourth element doping of Co in ternary Ni-Mn-Sn alloy may significantly enhance the saturation magnetization of the alloy and thus enhance the ΔSM. Here, the effects of Co-doping on the martensite transformation, magnetic properties and magnetocaloric effects (MCE) of quaternary Ni47−xMn43Sn10Cox (x = 0, 6, 11) alloys were investigated. The martensite transformation temperatures decrease while austenite Curie point increases with Co content increasing to x = 6 and 11, thus broadening the temperature window for a high magnetization austenite (13.5, 91.7 and 109.1 A·m2/kg for x = 0, 6 and 11, respectively). Two successive magnetostructural transformations (A → 10 M and A → 10 M + 6 M) occur in the alloy x = 6, which are responsible for the giant magnetic entropy change ΔSM = 29.5 J/kg·K, wide working temperature span ΔTFWHM = 14 K and large effective refrigeration capacity RCeff = 232 J/kg under a magnetic field of 5.0 T. These results suggest that Ni40.6Mn43.3Sn10.0Co6.1 alloy may act as a potential solid-state magnetic refrigerant working at room temperature.
“…Noteworthily, the RC eff of the present Co6 alloy reaches 223 J/kg, which is significantly larger than those of the stoichiometric Ni-Mn-based alloys 18,45,76,77,79,81–84 and is comparable to those of some Co-doped Mn-rich Ni-Mn-based compounds 1,63,78–80,83 . Besides, the achieved RC eff is also comparable to those rare-earth containing La(FeSi) 13 -based 72,73 and Gd 5 (SiGe) 4 -based 74,75 compounds. Of note is that the working temperature of the present alloy is slightly above 300 K, which is very encouraging for room-temperature magnetic refrigeration applications.Figure 8Effective magnetic refrigeration capacity RC eff and working temperature span under a magnetic field of 5.0 T for the present Co6 alloy and some most studied magnetocaloric materials, such as La(FeSi) 13 -based 72,73 , Gd 5 (SiGe) 4 -based 74,75 , NiMn-based 1,18,45,63,76–84 compounds.…”
Section: Resultsmentioning
confidence: 54%
“…Besides, the achieved RC eff is also comparable to those rare-earth containing La(FeSi) 13 -based 72,73 and Gd 5 (SiGe) 4 -based 74,75 compounds. Of note is that the working temperature of the present alloy is slightly above 300 K, which is very encouraging for room-temperature magnetic refrigeration applications.Figure 8Effective magnetic refrigeration capacity RC eff and working temperature span under a magnetic field of 5.0 T for the present Co6 alloy and some most studied magnetocaloric materials, such as La(FeSi) 13 -based 72,73 , Gd 5 (SiGe) 4 -based 74,75 , NiMn-based 1,18,45,63,76–84 compounds. These alloys were selected because their magnetocaloric effects (MCE) are all related to the first-order martensite transformation and are tested around the magnetostructural transition temperatures.…”
High magnetocaloric refrigeration performance requires large magnetic entropy change ΔSM and broad working temperature span ΔTFWHM. A fourth element doping of Co in ternary Ni-Mn-Sn alloy may significantly enhance the saturation magnetization of the alloy and thus enhance the ΔSM. Here, the effects of Co-doping on the martensite transformation, magnetic properties and magnetocaloric effects (MCE) of quaternary Ni47−xMn43Sn10Cox (x = 0, 6, 11) alloys were investigated. The martensite transformation temperatures decrease while austenite Curie point increases with Co content increasing to x = 6 and 11, thus broadening the temperature window for a high magnetization austenite (13.5, 91.7 and 109.1 A·m2/kg for x = 0, 6 and 11, respectively). Two successive magnetostructural transformations (A → 10 M and A → 10 M + 6 M) occur in the alloy x = 6, which are responsible for the giant magnetic entropy change ΔSM = 29.5 J/kg·K, wide working temperature span ΔTFWHM = 14 K and large effective refrigeration capacity RCeff = 232 J/kg under a magnetic field of 5.0 T. These results suggest that Ni40.6Mn43.3Sn10.0Co6.1 alloy may act as a potential solid-state magnetic refrigerant working at room temperature.
“…Recently, the origin of the spike has been attributed to the superheating of the FM state due to the magnetocaloric effect [20] or the alignment of magnetic domains [21]. DS M spikes have been observed in many materials such as MnAs [22] [17,25], La 1-x Pr xFe 11.5 Si 1.5 [26], and Mn 3 GaC [27]. The appearance of the spike is due to the incorrect application of the Maxwell relation.…”
Section: Resultsmentioning
confidence: 99%
“…The usual determination of DS M using magnetization data does not take into account magnetic irreversibility and usually results in erroneous spikes in the DS M estimations [16][17][18][19]. Recently, the origin of the spike has been attributed to the superheating of the FM state due to the magnetocaloric effect [20] or the alignment of magnetic domains [21].…”
LaFe 11.6 Si 1.4 alloy has been synthesized in polycrystalline form using both arc melting and spark plasma sintering (SPS). The phase formation, hysteresis loss and magnetocaloric properties of the LaFe 11.6 Si 1.4 alloys synthesized using the two different techniques are compared. The annealing time required to obtain the 1:13 phase is significantly reduced from 14 days (using the arc melting technique) to 30 min (using the SPS technique). The magnetic entropy change (DS M ) for the arc-melted LaFe 11.6 Si 1.4 compound, obtained for a field change of 5 -0T (decreasing field), was estimated to be 19.6 J kg -1 K -1 . The effective RCP at 5T of the arc-melted LaFe 11.6 Si 1.4 compound was determined to be 360 J kg -1 which corresponds to about 88 % of that observed in Gd. A significant reduction in the hysteretic losses in the SPS LaFe 11.6 Si 1.4 compound was observed. The DS M , obtained for a field change of 5 -0T (decreasing field), for the SPS LaFe 11.6 Si 1.4 compound decreases to 7.4 J kg -1 K -1 . The T C also shifts from 186 (arc-melted) to 230 K (SPS) and shifts the order of phase transition from first to second order, respectively. The MCE of the SPS LaFe 11.6 Si 1.4 compound spreads over a larger temperature range with the RCP value at 5T reaching 288 J kg -1 corresponding to about 70 % of that observed in Gd. At low fields, the effective RCP values of the arc-melted and spark plasma-sintered LaFe 11.6 Si 1.4 compounds are comparable, thereby clearly demonstrating the potential of SPS LaFe 11.6 Si 1.4 compounds in low-field magnetic refrigeration applications.
“…Compared to ZIF-8 and Cu(dhbc) 2 (4,4-bpy), the material is a good absorbent to capture CO 2 under the same conditions. According to Clausius-Clapeyron [35][36][37], the adsorption heat of CO 2 on the sample was calculated to be 22.18 KJ mol À1 , higher than ZIF-8 (15.93 kJ mol À1 ) [38].…”
A 3-D porous metal-organic framework [Cu(SiF 6 )(4,4 0 -bpy) 2 ] was reported to have high methane storage. The studies about [Cu(SiF 6 )(4,4 0 -bpy) 2 ] were only related with methane storage but information on detailed synthesis and characterization as well as adsorption properties of [Cu(SiF 6 )(4,4 0 -bpy) 2 ], especially the H 2 and CO 2 adsorption properties, was scarce. In this work, [Cu(SiF 6 )(4,4 0 -bpy) 2 ] has been synthesized by adjusting the molar ratio of the reagents, synthesis temperature, and crystallization time. This method for obtaining [Cu(SiF 6 )(4,4 0 -bpy) 2 ] at low temperature has not been reported before. Temperature played an important role in synthesis of the sample and low temperature was beneficial for synthesizing bigger sample. Adsorption isotherms for carbon dioxide and hydrogen were measured under high pressure. [Cu(SiF 6 )(4,4 0 -bpy) 2 ] exhibited H 2 storage up to 2.36 wt% at 18 bar and a high CO 2 capture up to 4.17 mmol g À1 at 298 K at 10 bar.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
