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Based on the high-temperature organometallic route (Sun et al. Science 287, 1989 (2000)), we have synthesized powders containing CoPt_3 single crystals with mean diameters of 3.3(2) nm and 6.0(2) nm and small log-normal widths…

Materials Science · Physics 2009-11-07 F. Wiekhorst , E. Shevchenko , H. Weller , J. Kötzler

The latent heat (L) associated with the orbital order-disorder transition at T_JT is found to depend significantly on the average particle size (d) of LaMnO3. It rises slowly with the decrease in d down to ~100 nm and then jumps by more…

Strongly Correlated Electrons · Physics 2007-05-23 Nandini Das , Parthasarathi Mondal , Dipten Bhattacharya

The superconducting transition temperature (TC) in nanostructured Pb remains nearly constant as the particle size is reduced from 65 to 7nm, below which size the superconductivity is lost rather abruptly. In contrast, there is a large…

Mesoscale and Nanoscale Physics · Physics 2009-04-24 Sangita Bose , Charudatta Galande , S. P. Chockalingam , Rajarshi Banerjee , Pratap Raychaudhuri , Pushan Ayyub

We report on dc and microwave experiments of the low-dimensional organic conductors (TMTSF)$_2$PF$_6$ and (TMTSF)$_2$ClO$_4$ along the $a$, $b^{\prime}$, and $c^*$ directions. In the normal state of (TMTSF)$_2$PF$_6$ below T=70 K, the dc…

Strongly Correlated Electrons · Physics 2009-11-10 M. Dressel , K. Petukhov , B. Salameh , P. Zornoza , T. Giamarchi

We present a detailed study of the magnetic behavior of iron-oxide (gamma-Fe2O3 and Fe3O4) nanoparticles constituents of ferrofluids (FF's) with average particle sizes <d> = 2.5 and 10 nm. The particles were dispersed in the frozen liquid…

Materials Science · Physics 2011-03-24 G. F. Goya , S. L. Gómez , S. M. Shibli

This study reports the synthesis and physical properties of polycrystalline Dy$_2$CoCrO$_6$ (DCCO) nanoparticles. Analysis of the powder X-ray diffraction (XRD) pattern using Rietveld refinement showed that the compound crystallizes in an…

Materials Science · Physics 2025-06-03 M. M. Islam , M. A. Islam , Rana Hossain , M. J. Hosen , M. D. I. Bhuyan

A Mn30 molecular cluster is established to be the largest single-molecule magnet (SMM) discovered to date. Magnetization versus field measurements show coercive fields of about 0.5 T at low temperatures. Magnetization decay experiments…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 W. Wernsdorfer , M. Soler , D. N. Hendrickson , G. Christou

We study the phenomenon of macroscopic quantum tunneling (MQT) in small Josephson junctions (JJ) with an externally applied magnetic field. The latter results in the appearance of the Fraunhofer type modulation of the current density along…

Superconductivity · Physics 2009-11-13 Yu. N. Ovchinnikov , A. Barone , A. A. Varlamov

We report appearance of superconductivity at 5K in NdO0.5F0.5BiS2 and supplement the discovery [1] of the same in layered sulfide based ZrCuSiAs type compounds. The bulk polycrystalline compound is synthesized by conventional solid state…

Superconductivity · Physics 2015-06-11 Rajveer Jha , Anuj Kumar , Shiva Kumar Singh , V. P. S. Awana

Thermomagnetic measurements are used to obtain the size distribution and anisotropy of magnetic nanoparticles. An analytical transformation method is described which utilizes temperature-dependent zero-field cooling (ZFC) magnetization data…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 R. S. DiPietro , H. G. Johnson , S. P. Bennett , T. J. Nummy , L. H. Lewis , D. Heiman

In an effort to understand the impact of nanostructuring on the magnetocaloric effect, we have grown and studied gadolinium in MgO/W(50 $\textrm{\AA}$)/[Gd(400 $\textrm{\AA}$)/W(50 $\textrm{\AA}$)]$_8$ heterostructures. The entropy change…

Mesoscale and Nanoscale Physics · Physics 2011-12-19 Casey W. Miller , D. V. Williams , N. S. Bingham , H. Srikanth

We report a comprehensive study of the electrical and magneto-transport properties of nanocrystals of La_0.67Ca_0.33MnO_3 (LCMO) (with size down to 15 nm) and La_0.5Sr_0.5CoO_3 (LSCO) (with size down to 35 nm) in the temperature range 0.3 K…

Mesoscale and Nanoscale Physics · Physics 2012-03-20 Tapati Sarkar , M. Venkata Kamalakar , A. K. Raychaudhuri

In view of better characterizing possible quantum effects in the dynamics of nanometric particles, we measure the effect on the relaxation of a slight heating cycle. The effect of the field amplitude is studied; its magnitude is chosen in…

Condensed Matter · Physics 2009-10-30 R. Sappey , E. Vincent , M. Ocio , J. Hammann

Quantum dots (QDs) are good model systems for fundamental studies of mesoscopic transport phenomena using thermoelectric effects because of their small size, electrostatically tunable properties and thermoelectric response characteristics…

Mesoscale and Nanoscale Physics · Physics 2016-11-16 Artis Svilans , Martin Leijnse , Heiner Linke

We report on the low temperature tunnel magnetoresistance (MR) in quasi one-dimensional (1D) nanofibers made of conjugated polymers. The MR voltage bias dependence reveals an enhancement (at low biases) and the oscillatory behavior at…

Statistical Mechanics · Physics 2009-12-09 H. J. Lee , A. N. Aleshin , S. H. Jhang , H. S. Kim , M. J. Goh , K. Akagi , J. S. Brooks , Y. W. Park

We study the phenomenon of macroscopic quantum tunneling (MQT) in a finite size Josephson junction (JJ) with an externally applied magnetic field. As it is well known, the problem of MQT in a point-like JJ is reduced to the study of the…

Superconductivity · Physics 2008-07-18 Yu. N. Ovchinnikov , A. Barone , A. A. Varlamov

We investigate the effects of magnetic and electric fields on electron wavefunction interactions in single walled carbon nanotube bundles. The magnetoresistance measurements performed at 4.2K and the dependence of the data upon the electric…

Mesoscale and Nanoscale Physics · Physics 2010-09-15 M. Salvato , M. Lucci , I. Ottaviani , M. Cirillo , S. Orlanducci , F. Toschi , M. L. Terranova

Dense systems of magnetic nanoparticles may exhibit dipolar collective behavior. However, two fundamental questions remain unsolved: i) whether the transition temperature may be affected by the particle anisotropy or it is essentially…

We report some unusual magnetic properties observed in CoFe2O4 based ferrofluid (with an average particle size of D = 6 nm). More precisely, in addition to the low-field ferromagnetic (FM) phase transition with an intrinsic Curie…

Materials Science · Physics 2017-08-29 S. Sergeenkov , C. Stan , C. P. Cristescu , M. Balasoiu , N. S. Perov , C. Furtado

Processing magnetocaloric materials into magnetic refrigerants with appropriate shapes is essential for the development of magnetic refrigeration systems. In this context, the impact of processing on the physical properties of…