Publications de George Cristian Vaju

Defects and localization in chemically-derived graphene

László Forró, Andrzej Sienkiewicz, Richard Gaal, Arnaud Magrez, Luka Ciric, Jacim Jacimovic, George Cristian Vaju

We have performed electron spin resonance (ESR) measurements on a large assembly of graphene oxide (GO) and reduced graphene oxide (RGO) flakes. In GO samples the Curie tail is coming from 1.4 x 10(18) cm(-3) of localized spins. Although reduction of GO wa ...

Amer Physical Soc2012

Pressure dependence of the large-polaron transport in anatase TiO2 single crystals

Helmuth Berger, László Forró, Richard Gaal, Arnaud Magrez, Jacim Jacimovic, George Cristian Vaju, Radomir Zikic

We have measured the pressure and temperature dependences of the resistivity and the thermoelectric power of anatase, TiO2. The resistivity varies with T-3 at high temperatures, and its absolute value is in the 1 Omega cm range. Below 60 K, the resistivity ...

IOP Publishing - EPL Association2012

Synthesis, electrical resistivity, thermo-electric power and magnetization of cubic ZnMnO3

László Forró, Andrzej Sienkiewicz, Richard Gaal, Arnaud Magrez, Zlatko Mickovic, Jacim Jacimovic, Rita Smajda, George Cristian Vaju

Cubic ZnMnO3 powder in the form of well-crystalline nanoflakes have been synthesized at low temperatures from a nitrate precursor. The electrical properties of cubic ZuMnO(3) samples have been established by DC resistivity (rho) and thermo-electric power ( ...

Elsevier2011

High-pressure study of anatase TiO2

Helmuth Berger, László Forró, Richard Gaal, Arnaud Magrez, Jacim Jacimovic, George Cristian Vaju

We report resistivity and thermo-electric power measurements of the anatase phase of TiO2 under pressure up to 2.3 GPa. Despite its transparent appearance, the single crystal of anatase exhibits a metallic-like resistivity above 60 K, at all pressures. The ...

2010

Evidence from thermodynamic measurements for a singlet crystal-field ground state in pyrochlore Tb2Sn2O7 and Tb2Ti2O7

George Cristian Vaju

The magnetic entropy variation for the ordered spin-ice Tb2Sn2O7 and the spin-liquid Tb2Ti2O7 measured up to similar to 20 K shows that the crystal-field ground state for both systems is a singlet split from the first excited level by a thermal energy of s ...

2010