Zobrazeno 1 - 10
of 517
pro vyhledávání: '"Papavassiliou G"'
Autor:
Gkoura, L., Diamantopoulos, G., Fardis, M., Homouz, D., Alhassan, S., Beazi-Katsioti, M., Karagianni, M., Anastasiou, A., Romanos, G., Hassan, J., Papavassiliou, G.
It is well known that water inside hydrophobic nano-channels diffuses faster than bulk water. Recent theoretical studies have shown that this enhancement depends on the size of the hydrophobic nanochannels. However, experimental evidence of this depe
Externí odkaz:
http://arxiv.org/abs/1911.08219
Autor:
Hassan, J., Diamantopoulos, G., Gkoura, L., Karayanni, M., Alhassan, S., Kumar, S. V., Katsiotis, M. S., Karagiannis, T., Fardis, M., Panopoulos, N., Kim, H. J., Katsioti, M., Papavassiliou, G.
Water, when confined at the nanoscale acquires extraordinary transport properties. And yet there is no direct experimental evidence of these properties at nanoscale resolution. Here, by using 2D NMR diffusion-relaxation (D-T2) and spin-lattice - spin
Externí odkaz:
http://arxiv.org/abs/1612.01161
Dimensionless thermoelectric figure of merit $ZT$ is investigated for two-dimensional organic conductors $\tau-(EDO-S,S-DMEDT-TTF)_2(AuI_2)_{1+y}$, $\tau$-(EDT-S,S-DMEDT-TTF)_2(AuI_2)_{1+y}$ and $\tau$-(P-S,S-DMEDT-TTF)_2(AuI_2)_{1+y}$ ($y \le 0.875$
Externí odkaz:
http://arxiv.org/abs/1002.3395
Autor:
Koumoulis, D., Panopoulos, N., Reyes, A., Fardis, M., Pissas, M., Douvalis, A., Bakas, T., Argyriou, D., Papavassiliou, G.
Hole doped transition metal oxides are famous due to their extraordinary charge transport properties, such as high temperature superconductivity (cuprates) and colossal magnetoresistance (manganites). Astonishing, the mother system of these compounds
Externí odkaz:
http://arxiv.org/abs/0910.4494
Autor:
Panopoulos, N., Koumoulis, D., Diamantopoulos, G., Belesi, M., Fardis, M., Pissas, M., Papavassiliou, G.
The physics underlying the complex glassy phenomena, which accompany the formation of polarons in optimally doped manganites (ODM) is a cumbersome issue with many unexplained aspects. In this article we present $^{139}$La and $^{55}$Mn NMR in the tem
Externí odkaz:
http://arxiv.org/abs/0909.1653
We studied by M\"{o}ssbauer spectroscopy the Na$_{0.82}$CoO$_2$ compound using 1% $^{57}$Fe as a local probe which substitutes for the Co ions. M\"{o}ssbauer spectra at T=300 K revealed two sites which correspond to Fe$^{3+}$ and Fe$^{4+}$. The exist
Externí odkaz:
http://arxiv.org/abs/cond-mat/0503662
We studied the crystal and magnetic structure of the La$_{1-x}$Ca$_{x}$MnO$_{3}$ compound for $(0.11\leq x\leq 0.175)$ using stoichiometric samples. For $x<0.13$ the system's ground state is insulating canted antiferromagnetic. For $0.13\le x \le 0.1
Externí odkaz:
http://arxiv.org/abs/cond-mat/0503253
Autor:
Papavassiliou, G., Pissas, M., Belesi, M., Fardis, M., Stamopoulos, D., Kontos, A., Hennion, M., Dolinsek, J., Ansermet, J. P., Dimitropoulos, C.
The study of strong electron correlations in transition metal oxides with modern microscopy and diffraction techniques unveiled a fascinating world of nanosize textures in the spin, charge, and crystal structure. Examples range from high $T_c$ superc
Externí odkaz:
http://arxiv.org/abs/cond-mat/0412371
Autor:
Pissas, M., Papavassiliou, G.
In this article a detailed study of La$_{1-x}$Ca$_x$MnO$_3$ ($0\leq x \leq 0.23$) phase diagram using powder x-ray diffraction and magnetization measurements is presented. Unfortunately, in the related literature no properly characterized samples hav
Externí odkaz:
http://arxiv.org/abs/cond-mat/0403543
Using M\"ossbauer and EPR spectroscopy we have studied the insulating ferromagnetic La$_{1-x}$Ca$_x$Mn$_{0.99}$$^{57}$Fe$_{0.01}$O$_3$ ($x=0.175$) compound prepared in air and reduced atmosphere. The average hyperfine field follows a mean field appro
Externí odkaz:
http://arxiv.org/abs/cond-mat/0403446