Foreword

Carbon based materials include nanographites, conducting carbon nanomaterials, carbon nanotubes, graphene oxides, nanodiamonds, hybrids like carbon nanotubes embedded into polymer composites or functionalized molecular groups. These compounds are being implemented in multiple architectures with versatile chemical bonding, organization and morphologies leading to the unique physical properties such as exceptional electrical, thermal, structural dependent dimensionalities, mechanical and tribological performances. For instance, pure diamond is an excellent electrical insulator while some graphite based materials are more or less good electrical conductors, depending on their composition and pre-treatment. Carbon and graphite foams are very good thermal insulators, even at very high temperatures. On the other hand, diamond is used for the heat sink in electronics due to its very high thermal conductivity. Mechanical properties of carbon materials also differ considerably, depending on the type of the material. Since carbon allotropes and hybrids materials may contain different chemical bonding, multi-functional compounds can be tailored for various applications in nanoelectronics, integrated optoelectronics, energy storage and conversion, sensors, biomedicine, etc., being both already implemented in working devices and currently under development.

Intrinsic electronic features originating from doping or structural defects critically contribute to physical properties of carbon-based materials. These features may be exhaustively characterized by various electron magnetic resonance techniques including continuous wave (CW) or pulse electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR) and other advanced electron magnetic resonance methods. Using a variety of complementary EPR techniques provides detailed insight into the local environment and the electronic peculiarity of defect structures in carbon-based systems. Moreover, extraordinary sensitivity of EPR techniques to the relaxation times (both spin-lattice and spin-spin) of paramagnetic species as well as the capability of selective control and detection of defects paves the way for the understanding of spin dynamics, which is extremely important in quantum computation or implementations of non-volatile memory devices. Thus, EPR techniques, based on different instrumental functionalities and methodologies, due to their specific window of time scales allow probing structural and electronic features of intrinsic and engineered spin systems in carbon based materials with the aim to open new challenges toward advanced and emerging technologies.