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Ultrafast lattice deformation of tens to hundreds of nanometer thick metallic crystals, after femtosecond laser excitation, was measured directly using 8.04 keV subpicosecond x-ray and 59 keV femtosecond electron pulses. Coherent phonons…

材料科学 · 物理学 2018-03-09 Runze Li , Kyle Sundqvist , Jie Chen , H. E. Elsayed-Ali , Peter M. Rentzepis

Discontinuous changes of the lattice parameters at the Mott metal-insulator transition are detected by high-resolution dilatometry on deuterated crystals of the layered organic conductor $\kappa$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Br. The…

强关联电子 · 物理学 2007-12-11 M. de Souza , A. Bruehl , Ch. Strack , B. Wolf , D. Schweitzer , M. Lang

We report the observation of large magnetocaloric effect near room temperature in antipervoskite SnCMn3. The maximal magnetic entropy change at the first-order ferrimagnetic-paramagnetic transition temperature (TC 279 K) is about…

强关联电子 · 物理学 2009-05-18 B. S. Wang , P. Tong , Y. P. Sun , X. Luo , X. B. Zhu , G. Li , X. D. Zhu , S. B. Zhang , Z. R. Yang , W. H. Song , J. M. Dai

The intermolecular lattice vibrations in small-molecule organic semiconductors have a strong impact on their functional properties. Existing models treat the lattice vibrations within the harmonic approximation. In this work, we use…

材料科学 · 物理学 2020-02-04 Maor Asher , Daniel Angerer , Roman Korobko , Yael Diskin-Posner , David A. Egger , Omer Yaffe

This work aims to present an analytical and numerical study of the magnetocaloric effects (MCE) providing realistic proposals about materials that should be chosen in the design of new refrigerator appliances around the room temperature.…

材料科学 · 物理学 2017-12-05 A. Boubekri , M. Y. El Hafidi , M. El Hafidi

Magnetic cooling has the potential to replace conventional gas compression refrigeration. Materials such as La(Fe,Si)$_{13}$ exhibit a sizeable first-order magnetocaloric effect, and it is possible to tailor the phase transition towards…

Magnetic entropy and adiabatic temperature changes in and above the room-temperature region has been measured for La0.7Sr0.3Mn1-xM'xO3 (M' = Al, Ti) by means of magnetization and heat capacity measurements in magnetic fields up to 6 T. The…

材料科学 · 物理学 2007-08-17 D. N. H. Nam , N. V. Dai , L. V. Hong , N. X. Phuc , S. C. Yu , M. Tachibana , E. Takayama-Muromachi

We employ an effective-field theory with correlations in order to study a magnetocaloric effect on a triangular Ising antiferromagnet, which is selectively diluted by non-magnetic impurities on one of the three sublattices. Such a dilution…

统计力学 · 物理学 2023-07-19 Michal Borovský , Milan Žukovič

The lattice dynamics of members of the M2Mo6Se6 family of materials with guest ions M = K, Rb, Cs, In, and Tl has been studied using inelastic x-ray scattering and Raman spectroscopy at room temperature, as well as by ab-initio…

Owing to a high degree of geometrical frustration an Ising antiferromagnet on a kagome lattice (IAKL) is known to exhibit no long-range ordering at any temperature, including the ground state. Nevertheless, at low temperatures it shows a…

统计力学 · 物理学 2020-07-08 M. Semjan , M. Žukovič

A coupling of the first-order paramagnetic-to-induced-ferromagnetic martensitic and the second-order antiferromagnetic-to-ferromagnetic metamagnetic transitions was found in MnNi0.8Fe0.2Ge alloy. Based on the coupling, a magneto-volume…

材料科学 · 物理学 2014-08-26 E. K. Liu , Z. Y. Wei , Y. Li , G. D. Liu , H. Z. Luo , W. H. Wang , H. W. Zhang , G. H. Wu

There is growing interest in using ultrafast light pulses to drive functional materials into nonequilibrium states with novel properties. The conventional wisdom is that above gap photoexcitation behaves similarly to raising the electronic…

While the vibrational thermodynamics of materials with small anharmonicity at low temperatures has been understood well based on the harmonic phonons approximation; at high temperatures, this understanding must accommodate how phonons…

材料科学 · 物理学 2015-10-20 Tian Lan

Solid state-refrigerants have generated worldwide interest owing to their growing potential for use in efficient and green cooling devices. Caloric effects could be obtained by manipulating their degrees of freedom such as magnetization,…

材料科学 · 物理学 2016-10-10 M. Balli , S. Jandl , P. Fournier , D. Z. Dimitrov

The temperature and pressure dependence of the thermal displacements and lattice parameters were obtained across the $\gamma \to \alpha$ phase transition of Ce using high-pressure, high-resolution neutron and synchrotron x-ray powder…

强关联电子 · 物理学 2009-11-10 I. -K. Jeong , T. W. Darling , M. J. Graf , Th. Proffen , R. H. Heffner , Yongjae Lee , T. Vogt , J. D. Jorgensen

Phonon densities of states (DOS) of bcc $\alpha$-$^{57}$Fe were measured from room temperature through the 1044K Curie transition and the 1185K fcc $\gamma$-Fe phase transition using nuclear resonant inelastic x-ray scattering. At higher…

材料科学 · 物理学 2015-06-19 L. Mauger , M. S. Lucas , J. A. Muñoz , S. J. Tracy , M. Kresch , Yuming Xiao , Paul Chow , B. Fultz

Magneto-structural instability in the ferromagnetic shape memory alloy of composition Ni$_2$Mn$_{1.4}$Sn$_{0.6}$ is investigated by transport and magnetic measurements. Large negative magnetoresistance is observed around the martensitic…

强关联电子 · 物理学 2009-11-13 S. Chatterjee , S. Giri , S. Majumdar , S. K. De

The effects of sintering temperature (Ts) and chemical substitution on the structural and magnetic properties of manganite compounds La1-xSrxMn1-yFeyO3 (0.025 <= x <= 0.7; y= 0.01,0.15) are explored in a search to optimize their…

材料科学 · 物理学 2024-04-30 N. Brahiti , M. Balli , M. Abbasi Eskandari , A. El Boukili , P. Fournier

High entropy alloys (HEAs) are promising magnetocaloric materials with tunable operating temperature conditions using compositional modifications. Here, we combine experiments and first principles based spin modelling to engineer…

Using x-ray powder diffraction technique at various temperatures and applied magnetic fields, we have studied the magnetostructural properties of Ce(Fe0.95Si0.05)2. The x-ray diffraction data establish quantitative relationships between…

强关联电子 · 物理学 2010-05-21 Arabinda Haldar , Niraj K. Singh , Ya. Mudryk , K. G. Suresh , A. K. Nigam , V. K. Pecharsky