scholarly journals Observation of enhanced magnetic entropy change near room temperature in Sr-site deficient La0.67Sr0.33MnO3 manganite

RSC Advances ◽  
2019 ◽  
Vol 9 (41) ◽  
pp. 23598-23606 ◽  
Author(s):  
B. Arun ◽  
V. R. Akshay ◽  
M. Vasundhara
Keyword(s):  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy

The effect of Sr-site deficiency on the structural, magnetic and magnetic entropy change of La0.67Sr0.33−yMnO3−δ (y = 0.18 and 0.27) compounds was investigated.

Refrigerant Capacity and Magnetocaloric Effect on LaFe11.1Co0.8Si1.1BX Alloys

2011 ◽  
Vol 84-85 ◽  
pp. 667-670
Author(s):  
Guo Qiu Xie
Keyword(s):  
Magnetocaloric Effect ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Field Change ◽  
Refrigerant Capacity ◽  
Structure Phase ◽  
Magnetic Field Change ◽  
Cubic Structure

In this paper, we report on the structure, magnetic properties and magnetocaloric effect in NaZn13-type LaFe11.1Co0.8Si1.1Bxalloys close to room temperature. The stable NaZn13cubic structure phase (space group isFm-3c) can easily obtained by annealing at 1080 °C for 225 hours. The maximal values of magnetic entropy change for LaFe11.1Co0.8Si1.1Bx(x=0.2, 0.25) were found to be 5.3 and 5.9 J/kg K at Curie temperature for a magnetic field change in 0-1.5 T, respectively. The calculated refrigerant capacity for a field change in 0–1.5 T is about 147 and 107 J/kg K, for LaFe11.1Co0.8Si1.1B0.2and LaFe11.1Co0.8Si1.1B0.25respectively, which is as larger as those of Gd(99.3%) alloy

scholarly journals Extremely Large Magnetic Entropy Change of MnAs1-xSbx near Room Temperature

2002 ◽  
Vol 43 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Hirofumi Wada ◽  
Kentaro Taniguchi ◽  
Yuji Tanabe
Keyword(s):  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy

Room-temperature magnetic entropy change in La0.7 Sr0.3 Mn1-x Mx O3 (M = Al, Ti)

2007 ◽  
Vol 244 (12) ◽  
pp. 4570-4573 ◽  
Author(s):  
N. V. Dai ◽  
D. V. Son ◽  
S. C. Yu ◽  
L. V. Bau ◽  
L. V. Hong ◽  
...  
Keyword(s):  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy

scholarly journals Phase formation and magnetocaloric effect in (Pr,Nd)-Fe alloys prepared by rapidly quenched method

2018 ◽  
Vol 185 ◽  
pp. 05002
Author(s):  
Dan Nguyen ◽  
Ha Nguyen ◽  
An Nguyen ◽  
Yen Nguyen ◽  
Thanh Pham ◽  
...  
Keyword(s):  
Temperature Region ◽  
Melt Spinning ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Annealing Conditions ◽  
Different Temperatures ◽  
Fe Alloys ◽  
Bulk Alloys

In this work, Pr2-xNdxFe17 (x = 0 - 2) ribbons with thickness of about 15 μm were prepared by melt-spinning method. The alloy ribbons were then annealed at different temperatures (900 - 1100°C) for various time (0.25 - 2 h). The formation of the (Pr,Nd)2Fe17 (2:17) crystalline phase in the alloys strongly depends on the Pr/Nd ratio and annealing conditions. Annealing time for the completed formation of the 2:17 phase in the rapidly quenched ribbons is greatly reduced in comparison with that of bulk alloys. Curie temperature, TC, of the alloys can be controlled in room temperature region by changing Pr/Nd ratio. Maximum magnetic entropy change (|ΔSm|max) and full width at haft the maximum peak (FWHM) of the magnetic entropy change of the alloys were respectively found to be larger than 1.5 J.kg−1K−1 and 40 K in room temperature region with magetic field change ΔH = 12 kOe.

Large Room Temperature Magnetocaloric Effect in Ni50Mn34(Co,Cu)In15

2013 ◽  
Vol 316-317 ◽  
pp. 996-1001 ◽  
Author(s):  
Zhe Li ◽  
Chao Jing ◽  
Jun Jun Wu ◽  
Ling Xian Wu ◽  
Jian Yin ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Exchange Interaction ◽  
Magnetocaloric Effect ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Parent Phase ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Room Temperature Magnetic Refrigeration ◽  
Ferromagnetic Ordering

Effect of Co or Cu slightly introduced in Ni50Mn35In15on martensitic transformation and magnetocaloric effect was investigated. The small doping of Co can modify exchange interaction between Mn atoms, resulting in the ferromagnetic ordering of the parent phase and a large magnetization difference across the martensitic transformation. For Cu-doped sample, a large was obtained, and gives rise to a large magnetic entropy change of 58.4 J/kg K for 5 T near room temperature accompanying with smaller hysteresis losses. The study on the doping system may have significant impact on realization of room-temperature magnetic refrigeration.

Magnetism and magnetic entropy change in LaFe 11 Al 2 C x compounds around room temperature

2004 ◽  
Vol 13 (3) ◽  
pp. 393-396 ◽  
Author(s):  
Wang Fang ◽  
Chen Yuan-Fu ◽  
Wang Guang-Jun ◽  
Sun Ji-Rong ◽  
Shen Bao-Gen
Keyword(s):  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy

Observation of Griffiths Phase, Critical Exponent Analysis and High Magnetocaloric Effect Near Room Temperature at Low Magnetic Field in V doped La0.7Sr0.3MnO3

2022 ◽  
Author(s):  
Jagadish Kumar Galivarapu ◽  
Ashika Jose ◽  
Erappanal Padmanabhan Jinu ◽  
Thirumalainaidu Thiagarajan Saravanan ◽  
Senthil Kumar Eswaran ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Curie Temperature ◽  
Critical Exponent ◽  
Critical Exponents ◽  
Room Temperature ◽  
Magnetic Entropy Change ◽  
Entropy Change ◽  
Magnetic Entropy ◽  
Griffiths Phase ◽  
Vanadium Doping

Abstract We report on observation of Griffiths phase, high magnetocaloric properties at low magnetic fields and temperature dependent critical exponents of La0.7Sr0.3VxMn1-xO3 (x=0, 0.05 & 0.1) perovskite bulk materials. The Curie temperature (TC) of pure La0.7Sr0.3MnO3 is seen to be 368.7 K and decreases towards room temperature (342.2 K) by 10 mol% vanadium doping at the Mn site. Vanadium doping leads to enhancement in magnetic entropy change (-SM) from 1 Jkg-1K-1to 1.41 Jkg-1K-1. Vanadium doping at Mn site leads to the formation of Griffiths phase, a magnetic disorder due to the co-existence of paramagnetic matrix and short range ferromagnetic clusters. X-ray photoelectron spectroscopy analysis confirm the presence of mixed valance V4+/V5+along with Mn3+/ Mn4+ ions contributing to various double exchange interactions. Nature of phase transitions and magnetic interactions are analyzed by evaluating critical exponents and. All the samples show second-order ferromagnetic (FM) to paramagnetic (PM) phase transition, confirmed from the modified Arrott’s plots and critical exponent analysis carried out using Kouvel-Fisher method. Enhancement in magnetic entropy change along with the decrease in Curie temperature towards room temperature by vanadium doping in the La0.7Sr0.3MnO3 oxides indicates the possible application of these materials for the magnetic refrigeration at low magnetic fields.

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