Magnetic Resonance Studies of Solid-State Hydrogen and Hydrogen-Related Defects
Hydrogen is a detrimental impurity in many chemical vapor deposited (CVD) materials, particularly those involved in electronic or optical applications. For example, active hydrogen defects have been observed in materials such as silicon, Si, gallium arsenide, GaAs, and diamond, C, thin films. Hydrogen and its related defects can be identified, quantified, and observed using magnetic resonance techniques. These techniques allow a unique quantitative, non-destructive view of hydrogen in the solid-state. Nuclear magnetic resonance (NMR) is used to study hydrogenated defects directly, while electron paramagnetic resonance (EPR) is used to observe hydrogen associated with paramagnetic defects. These observations can enhance our understanding of the effects of hydrogen incorporation on the properties of such materials.
Abstract The spin-phonon spin 1 2 Heisenberg system is found to have the same critical index for the susceptibility as the ideal, rigid lattice ferromagnet. This is in accordance with the criterion for critical index renormalisation expounded by Fisher in terms of the sign of the specific heat index.