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Title: Critical behavior and magnetocaloric effect of Pr{sub 1−x}Ca{sub x}MnO{sub 3}

Abstract

The critical behavior of Pr{sub 1−x}Ca{sub x}MnO{sub 3} samples with x = 0.25, 0.27, and 0.29 has been investigated. Detailed analyses of magnetic-field dependences of magnetization at temperatures around the paramagnetic-ferromagnetic transition, M(H, T), reveal that the samples undergo a second-order magnetic phase transition. The Arrott plot method predicts the values of critical parameters to be T{sub C}  ≈ 118 K, β = 0.351 ± 0.003, γ = 1.372 ± 0.002, and δ = 4.90 ± 0.02 for x = 0.25; T{sub C}  ≈ 116 K, β = 0.362 ± 0.002, γ = 1.132 ± 0.004, and δ = 4.09 ± 0.03 for x = 0.27; and T{sub C}  ≈ 110 K, β = 0.521 ± 0.002, γ = 0.912 ± 0.005, and δ = 2.71 ± 0.02 for x = 0.29. The values of β = 0.351 (for x = 0.25) and β = 0.362 (for x = 0.27) are close to the value β = 0.365 expected for the 3D Heisenberg model, proving an existence of short-range ferromagnetic interactions in these samples. A slight increase in Ca-doping content (x = 0.29) leads to the shift of the β value (=0.521) towards that of the mean-field theory (with β = 0.5) characteristic of long-range ferromagnetic interactions. The samples also exhibit a magnetocaloric effect: around T{sub C} of Pr{sub 1−x}Ca{sub x}MnO{sub 3} compounds, magnetic-entropy change reaches the maximum values of about 5.0, 4.1, and 2.5 J kg{sup −1} K{sup −1} for x = 0.25, 0.27, and 0.29, respectively, under an applied-field change of 50 kOe. Magnetic-field dependences of the maximum magnetic-entropy change (ΔS{sub max}) obey a power law |ΔS{sub max}(H)|more » ∝ H{sup n}, where exponent values n = 0.68–0.74 are close to those obtained from the theoretical relation n = 1 + (β − 1)/(β + γ)« less

Authors:
; ;  [1];  [1];  [2]; ;  [3];  [4];  [5];  [6]
  1. Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)
  2. (Viet Nam)
  3. Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093-0411 (United States)
  4. Institute of Chemistry, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi (Viet Nam)
  5. Faculty of Engineering Physics and Nanotechnology, VNU University of Engineering and Technology, 144 Xuan Thuy, Cau Giay, Hanoi (Viet Nam)
  6. Department of Nanoscience and Nanotechnology, Advanced Institute for Science and Technology, Hanoi University of Science and Technology, 01 Dai Co Viet, Hai Ba Trung, Hanoi (Viet Nam)
Publication Date:
OSTI Identifier:
22410058
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CALCIUM COMPOUNDS; CONCENTRATION RATIO; ENTROPY; FERROMAGNETISM; HEISENBERG MODEL; MAGNETIC FIELDS; MAGNETIC PROPERTIES; MAGNETIZATION; MANGANATES; MEAN-FIELD THEORY; PARAMAGNETISM; PHASE TRANSFORMATIONS; PRASEODYMIUM COMPOUNDS

Citation Formats

Ho, T. A., Phan, The-Long, Yu, S. C., E-mail: scyu@chungbuk.ac.kr, Thanh, T. D., Institute of Materials Science, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi, Yu, Yikyung, Tartakovsky, D. M., Ho, T. O., Thang, P. D., and Le, Anh-Tuan. Critical behavior and magnetocaloric effect of Pr{sub 1−x}Ca{sub x}MnO{sub 3}. United States: N. p., 2015. Web. doi:10.1063/1.4914537.
Ho, T. A., Phan, The-Long, Yu, S. C., E-mail: scyu@chungbuk.ac.kr, Thanh, T. D., Institute of Materials Science, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi, Yu, Yikyung, Tartakovsky, D. M., Ho, T. O., Thang, P. D., & Le, Anh-Tuan. Critical behavior and magnetocaloric effect of Pr{sub 1−x}Ca{sub x}MnO{sub 3}. United States. doi:10.1063/1.4914537.
Ho, T. A., Phan, The-Long, Yu, S. C., E-mail: scyu@chungbuk.ac.kr, Thanh, T. D., Institute of Materials Science, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi, Yu, Yikyung, Tartakovsky, D. M., Ho, T. O., Thang, P. D., and Le, Anh-Tuan. Thu . "Critical behavior and magnetocaloric effect of Pr{sub 1−x}Ca{sub x}MnO{sub 3}". United States. doi:10.1063/1.4914537.
@article{osti_22410058,
title = {Critical behavior and magnetocaloric effect of Pr{sub 1−x}Ca{sub x}MnO{sub 3}},
author = {Ho, T. A. and Phan, The-Long and Yu, S. C., E-mail: scyu@chungbuk.ac.kr and Thanh, T. D. and Institute of Materials Science, Vietnam Academy of Science and Technology, 18-Hoang Quoc Viet, Hanoi and Yu, Yikyung and Tartakovsky, D. M. and Ho, T. O. and Thang, P. D. and Le, Anh-Tuan},
abstractNote = {The critical behavior of Pr{sub 1−x}Ca{sub x}MnO{sub 3} samples with x = 0.25, 0.27, and 0.29 has been investigated. Detailed analyses of magnetic-field dependences of magnetization at temperatures around the paramagnetic-ferromagnetic transition, M(H, T), reveal that the samples undergo a second-order magnetic phase transition. The Arrott plot method predicts the values of critical parameters to be T{sub C}  ≈ 118 K, β = 0.351 ± 0.003, γ = 1.372 ± 0.002, and δ = 4.90 ± 0.02 for x = 0.25; T{sub C}  ≈ 116 K, β = 0.362 ± 0.002, γ = 1.132 ± 0.004, and δ = 4.09 ± 0.03 for x = 0.27; and T{sub C}  ≈ 110 K, β = 0.521 ± 0.002, γ = 0.912 ± 0.005, and δ = 2.71 ± 0.02 for x = 0.29. The values of β = 0.351 (for x = 0.25) and β = 0.362 (for x = 0.27) are close to the value β = 0.365 expected for the 3D Heisenberg model, proving an existence of short-range ferromagnetic interactions in these samples. A slight increase in Ca-doping content (x = 0.29) leads to the shift of the β value (=0.521) towards that of the mean-field theory (with β = 0.5) characteristic of long-range ferromagnetic interactions. The samples also exhibit a magnetocaloric effect: around T{sub C} of Pr{sub 1−x}Ca{sub x}MnO{sub 3} compounds, magnetic-entropy change reaches the maximum values of about 5.0, 4.1, and 2.5 J kg{sup −1} K{sup −1} for x = 0.25, 0.27, and 0.29, respectively, under an applied-field change of 50 kOe. Magnetic-field dependences of the maximum magnetic-entropy change (ΔS{sub max}) obey a power law |ΔS{sub max}(H)| ∝ H{sup n}, where exponent values n = 0.68–0.74 are close to those obtained from the theoretical relation n = 1 + (β − 1)/(β + γ)},
doi = {10.1063/1.4914537},
journal = {Journal of Applied Physics},
number = 17,
volume = 117,
place = {United States},
year = {Thu May 07 00:00:00 EDT 2015},
month = {Thu May 07 00:00:00 EDT 2015}
}
  • We have investigated the role of the stress induced by the presence of the substrate in thin films of colossal magnetoresistive manganites on structural, resistive, and magnetic properties. Because of the strong coupling between the small structural distortions related to the charge ordering (CO) and the resistive properties, the presence of the substrate prevents the full development of the charge ordering in Pr{sub 0.5}Ca{sub 0.5}MnO{sub 3}, especially in the very thin films. For thicker films, the CO state exists, but is not fully developed. Correlatively, the magnetic field which is necessary to suppress the CO is decreased drastically from 25more » T to about 5 T on SrTiO{sub 3} substrates. We have also investigated the influence of the doping level by studying the case of Pr{sub 0.6}Ca{sub 0.4}MnO{sub 3}. {copyright} 2001 American Institute of Physics.« less
  • We have investigated the magnetocaloric effect along with magnetic phase transition and critical exponent analysis in mixed manganite La{sub 0.67}Sr{sub 0.33}Mn{sub 1−x}V{sub x}O{sub 3} (0≤x≤0.15). To determine the nature of the paramagnetic to ferromagnetic phase transition, found to be of second-order, we performed a critical exponents study by dc-magnetization M(H,T) measurements around the Curie temperature T{sub C}. Modified Arrott plot method has been adopted to study the critical behavior of the compounds at their transition region, the values of critical exponents β, γ and δ are close to those expected for three-dimensional Heisenberg class with short-range interaction. A large magneticmore » entropy change |ΔS{sub M}| deduced from isothermal magnetization curves, has been observed in our samples with a peak centered on their respective T{sub C}. With increase in vanadium content, the temperature corresponding to the maximum entropy change as well as the magnetic transition temperature gradually shifts to low temperatures. The field dependence of the magnetic entropy change is also analyzed, which shows the power law dependence namely, ΔS{sub M}∝H{sup n}. Relative cooling power increases from 205 J/kg for x=0.00 to 258 J/Kg for x=0.15 making these materials a promising candidates for magnetic refrigeration near room temperature. - Graphical abstract: Scaling plot below and above T{sub C} using the β and γ exponents determined from the Arrot plot method of La{sub 0.67}Sr{sub 0.33}Mn{sub 1−x}V{sub x}O{sub 3} for x=0.15. - Highlights: • The paramagnetic to ferromagnetic phase transition of La{sub 0.67}Sr{sub 0.33}Mn{sub 1−x}V{sub x}O{sub 3} (0≤x≤0.15) is found to be of second-order. • The field dependence of the magnetic entropy shows the power law dependence namely, ΔS{sub M}∝H{sup n}. • Moderate values of −ΔS{sub M}{sup max} and RCP make the La{sub 0.67}Sr{sub 0.33}Mn{sub 1−x}V{sub x}O{sub 3} compounds potential candidates for magnetic refrigeration applications.« less
  • Electron energy-loss spectroscopy (EELS) has been used to determine the valence state of manganese for all the samples at low temperature (93 K). EELS results indicate that the valence state of manganese keeps constant ({similar_to}3.5) for all the samples. The effects of the A-site cation size mismatch on the charge ordering (CO) behaviors in the manganites (La{sub 1{minus}x}Y{sub x}){sub 0.5}(Ca{sub 1{minus}y}Sr{sub y}){sub 0.5}MnO{sub 3} are studied by transmission electron microscopy (TEM). TEM images show that the size mismatch and disorder of A-site cations have a suppression effect on the CO transition. The schematic models are proposed for the incommensurate COmore » modulation in the samples with size mismatch {sigma}{sup 2}{le}0.003. The disappearance of the CO transition in the sample with the largest mismatch ({sigma}{sup 2}=0.005) is explained by the random arrangements of Mn{sup 3+} and Mn{sup 4+} ions. {copyright} 2001 American Institute of Physics.« less
  • The La{sub 0.8}Na{sub 0.1}MnO{sub 3} oxide was prepared by the solid-state reaction and annealed in air. The X-ray diffraction data reveal that the sample is crystallized in a rhombohedral structure with R3{sup ¯}c space group. Magnetic study shows a second-order magnetic phase transition from ferromagnetic to paramagnetic state at the Curie temperature T{sub C} = 295 K. In addition, the magnetizations as a function of temperature and the magnetic field is used to evaluate the magnetic entropy change ΔS{sub M}. Then, we have deduced that the La{sub 0.8}Na{sub 0.1}MnO{sub 3} oxide has a large magnetocaloric effect at room temperature. Such effect is givenmore » by the maximum of the magnetic entropy change ΔS{sub Mmax} = 5.56, and by the Relative cooling power (RCP) factor which is equal to 235 under a magnetic field of 5 T. Moreover, the magnetic field dependence of the magnetic entropy change is used to determine the critical exponents β, γ, and δ which are found to be β = 0.495, γ = 1.083, and δ = 3.18. These values are consistent with the prediction of the mean field theory (β = 0.5, γ = 1, and δ = 3). Above all, the temperature dependence of electrical resistivity shows a metal–insulator transition at T{sub ρ}. The electrical resistivity decrease when we apply a magnetic field giving a magnetoresistance effect in the order of 60% at room temperature.« less
  • Highlights: • Synthesis of magnetic ceramic composites. • Magnetization of dual phase ceramics. • Magnetic entropy change in (0.95)La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/(0.05)Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} solid solution. - Abstract: We report the magnetic and magnetocaloric properties of (0.95)La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/(0.05)Ni{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x = 0.0, 0.1, 0.3, and 0.5) ceramic composites. The composite samples with nominal compositions were prepared using the conventional solid-state reaction method. The phase purity and structure were confirmed by using X-ray diffraction. Temperature dependent magnetization measurements and Arrott analysis reveal second order of magnetic phase transition in the composite samples. A maximummore » in magnetic entropy change of ∼0.75 J/kg K at 1 T has been observed in (0.95)La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/(0.05)NiFe{sub 2}O{sub 4} sample. The values of magnetic entropy change of these composites make them attractive for potential applications. These composite samples may consider as potential material for magnetic refrigeration near room temperature.« less