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Intermetallic compounds with the overall formula MnFePAsGe ( varies from 0 to 0.1) were investigated in order to study their magnetocaloric effect by monitoring the adiabatic temperature change, magnetic entropy change and their relation to structural parameters. It was found that the maximum of magnetocaloric effect was achieved for = 0.02. Adiabatic temperature change for consolidated powder was equal to 2.75 K for the magnetic field change ΔB = 1.7 T for the sample with = 0.02. For the pure non-doped sample, this parameter is much lower: ΔT = 1.7 K @ ΔB = 1.7 T. This result was correlated with the change of structural parameters such as lattice constants and the unit cell volume.
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http://dx.doi.org/10.3390/ma10050529 | DOI Listing |
Phys Rev Lett
August 2025
RIKEN Center for Quantum Computing, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
We present a method for probing the quantum capacitance associated with the Rydberg transition of surface electrons on liquid helium using radio-frequency (rf) reflectometry. Resonant microwave excitation of the Rydberg transition induces a redistribution of image charges on capacitively coupled electrodes, giving rise to a quantum capacitance originating from adiabatic state transitions and the finite curvature of the energy bands. By applying frequency-modulated resonant microwaves to drive the Rydberg transition, we systematically measured a capacitance sensitivity of 0.
View Article and Find Full Text PDFJ Phys Chem A
September 2025
Univ. Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, Rennes F-35000, France.
We present the first dataset of collisional (de)-excitation rate coefficients of HCN induced by CO, one of the main perturbing gases in cometary atmospheres. The dataset spans the temperature range of 5-50 K. It includes both state-to-state rate coefficients involving the lowest ten and nine rotational levels of HCN and CO, respectively, and the so-called "thermalized" rate coefficients over the rotational population of CO at each kinetic temperature.
View Article and Find Full Text PDFMicromachines (Basel)
August 2025
College of Mechanical Engineering, Tianjin University of Technology and Education, Tianjin 300222, China.
Titanium alloys (Ti-6Al-4V) are widely used in the aerospace field. However, as a typical difficult-to-machine material, titanium alloys have a low thermal conductivity, a high chemical activity, and a significant adiabatic shear effect. In conventional milling (CM), the temperature in the cutting zone rises sharply, leading to tool adhesion, rapid wear, and damage to the workpiece surface.
View Article and Find Full Text PDFAcc Chem Res
August 2025
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
ConspectusAdiabatic demagnetization refrigeration (ADR), which exploits the magnetocaloric effect (MCE), remains the only helium-free refrigeration technology capable of reaching temperatures below 1 K. With the rapid growth of quantum computing and astronomical observation, there is a pressing need for large-capacity ADR systems─underscoring the critical demand for magnetic refrigerants capable of generating substantial magnetic entropy changes (-Δ) at millikelvin temperatures. However, a long-standing challenge persists: achieving both large -Δ values and low magnetic ordering temperatures ().
View Article and Find Full Text PDFPhys Chem Chem Phys
August 2025
Polymers and Functional Materials Department, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India.
A series of Bi-doped manganites, , LaBiSrMnO ( = 0.05, 0.1, 0.
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