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We present a theoretical survey of ferromagnetic transition temperatures in cubic (III,Mn)V semiconductors based on a model with $S=5/2$ local moments exchange-coupled to itinerant holes in the host semiconductor valence band. Starting from…

材料科学 · 物理学 2016-08-16 T. Jungwirth , Jürgen König , Jairo Sinova , J. Kučera , A. H. MacDonald

We report $^{51}$V nuclear magnetic resonance (NMR) studies on single crystals of the multiferroic material FeVO$_4$. The high-temperature Knight shift shows Curie-Weiss behavior, $^{51}K = a/(T + \theta)$, with a large Weiss constant…

强关联电子 · 物理学 2014-05-16 J. Zhang , L. Ma , J. Dai , Y. P. Zhang , Z. Z. He , B. Normand , Weiqiang Yu

Within the nuclear Fermi-liquid drop model, quantum and thermal fluctuations are considered by use of the Landau-Vlasov-Langevin equation. The spectral correlation function of the nuclear surface fluctuations is evaluated in a simple model…

核理论 · 物理学 2009-10-30 D. Kiderlen , V. M. Kolomietz , S. Shlomo

The epoxy/magnetite nanocomposites express superparamagnetism under a static or low-frequency electromagnetic field. At the microwave frequency, said the X-band, the nanocomposites reveal an unexpected diamagnetism. To explain the…

介观与纳米尺度物理 · 物理学 2021-01-18 Che-Hao Chang , Shih-Chieh Su , Tsun-Hsu Chang , Ching-Ray Chang

Frequency-dependent terahertz conductivities of La$_{2-x}$Sr$_x$CuO$_4$ thin films with various carrier concentrations were investigated. The imaginary part of the complex conductivity considerably increased from far above a zero-resistance…

超导电性 · 物理学 2012-03-29 Daisuke Nakamura , Yoshinori Imai , Atsutaka Maeda , Ichiro Tsukada

We have investigated the magnetic properties of nanocrystalline LaCo0.5Mn0.5O3. The temperature dependence of the imaginary part of the a.c. susceptibility shows a strongly frequency dependent maximum at a temperature, Tf, which is well…

材料科学 · 物理学 2007-05-23 R. Mahendiran , Y. Breard , M. Hervieu , B. Raveau , P. Schiffer

We perform magnetic susceptibility and magnetic torque measurements on the organic $\kappa$-(BEDT-TTF)$_2$Hg(SCN)$_2$Br, which is recently suggested to host an exotic quantum dipole-liquid in its low-temperature insulating phase. Below the…

LaCoO3 (LCO) nanoparticles were synthesized and their magnetic and structural properties were examined using SQUID magnetometery and neutron diffraction. The nanoparticles exhibit ferromagnetic long-range order beginning at T_C…

强关联电子 · 物理学 2013-11-04 A. M. Durand , D. P. Belanger , F. Ye , S. Chi , J. A. Fernandez-Baca , C. H. Booth , M. Bhat

The magnetic behaviour of SmN has been investigated in stoichiometric polycrystalline films. All samples show ferromagnetic order with Curie temperature (T_c) of 27 +/- 3 K, evidenced by the occurrence of hysteresis below T_c. The…

强关联电子 · 物理学 2009-11-13 C. Meyer , B. J. Ruck , J. Zhong , S. Granville , A. R. H. Preston , G. V. M. Williams , H. J. Trodahl

We consider the temperature fluctuations of a small object. Classical fluctuations of the temperature have been considered for a long time. Using the Nyquist approach, we show that the temperature of an object fluctuates when in a thermal…

统计力学 · 物理学 2015-06-24 A. V. Balatsky , Jian-Xin Zhu

We show that antiferromagnetic susceptibility in ferritin increases with temperature between 4.2 K and 180 K (i. e. below the N\'{e}el temperature) when taken as the derivative of the magnetization at high fields ($30\times10^4$ Oe). This…

强关联电子 · 物理学 2009-11-13 N. J. O. Silva , A. Millan , F. Palacio , E. Kampert , U. Zeitler , H. Rakoto , V. S. Amaral

The shape of temperature dependence of spontaneous magnetization was analyzed on about forty ferromagnetic materials. The shape squareness was determined from the magnetization curves fits by the superellipse equation (Lame curve). The…

材料科学 · 物理学 2026-04-07 A. Perevertov

We analyze the anomalies of superconducting state (s and d-wave pairing) in a simple model of pseudogap state, induced by fluctuations of short - range order (e.g. antiferromagnetic), based on the model Fermi surface with "hot patches". We…

超导电性 · 物理学 2009-10-31 E. Z. Kuchinskii , M. V. Sadovskii

We study superconductivity in paramagnetic and ferromagnetically-ordered phases in a two-dimensional electron system with parabolic fermionic dispersion and short-range repulsive interaction. In the paramagnetic phase, we find that a weak…

超导电性 · 物理学 2025-07-11 Zachary M Raines , Andrey V Chubukov

We report a study in which Point contact Andreev reflection (PCAR) spectroscopy using superconducting Nb tip has been carried out on NdNi5, a ferromagnet with a Curie temperature of TC~7.7K. The measurements were carried out over a…

超导电性 · 物理学 2007-05-23 Sourin Mukhopadhyay , Pratap Raychaudhuri , Devang A. Joshi , C. V. Tomy

There has been a paradigm shift from the well-known laws of thermal radiation derived over a century ago, valid only when the length scales involved are much larger than the thermal wavelength (around 10 $\mu$m at room temperature), to a…

应用物理 · 物理学 2024-02-20 Pierre-Olivier Chapuis , Bong Jae Lee , Alejandro Rodriguez

We report combined magnetic susceptibility, dielectric constant, nuclear quadruple resonance (NQR) and zero-field nuclear magnetic resonance (NMR) measurements on single crystals of multiferroics CuBr$_2$. High quality of the sample is…

A new class of superparamagnetism was found in relaxor ferroelectric 2/3BiFeO$_{3}$-1/3BaTiO$_{3}$. The size of the magnetic particle, estimated from the superparamagnetic magnetization curve, coincides with the size of the polar nanoregion…

材料科学 · 物理学 2015-05-27 Minoru Soda , Masato Matsuura , Yusuke Wakabayashi , Kazuma Hirota

Based on the classical Langevin equation, we have re-visited the problem of orbital motion of a charged particle in two dimensions for a normal magnetic field crossed with or without an in-plane electric bias. We are led to two interesting…

介观与纳米尺度物理 · 物理学 2009-11-13 Dibyendu Roy , N. Kumar

Time-resolved pump-probe measurements were made at variable heat accumulation in Co/Pd superlattices. Heat accumulation increases the baseline temperature and decreases the equilibrium magnetization. Transient ultrafast demagnetization…

介观与纳米尺度物理 · 物理学 2018-05-09 F. Hoveyda , E. Hohenstein , R. Judge , S. Smadici