Lithium colloids and color center creation in electron-irradiated Li2NH observed by electron-spin resonance

Francois Beuneu (1) , Peter Vajda (1) , Y. Nakamori (2) , S. Orimo (2)

1 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory
2 Institute for Materials Research

We have irradiated Li2NH powder with MeV electrons at room temperature and investigated the introduced defects with electron spin resonance. CESR indicates the presence of nanosize metallic Li colloids seen as a Lorentzian line with a g = 2.0023 and a line width DeltaH = 50 microT. A second, broader, signal (DeltaH = 3 to 4 mT) appears superimposed upon the Li line at low T (Curie-type behavior) which exhibits complex T-dependence with a break near 180 K for its g-value and DeltaH. We are suggesting for the latter a vacancy-type defect in the NH-sublattice, with freezing of its H-component below 180 K. When heated both the Li colloids and the color centers anneal around 100 C probably due to hydrogen evolution and subsequent chemical degradation.

Mots clés: lithium; colloids; irradiation; Li2NH

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Francois Beuneu, Peter Vajda, Y. Nakamori, S. Orimo. Lithium colloids and color center creation in electron-irradiated Li2NH observed by electron-spin resonance. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2006, 74, pp.174122. ⟨10.1103/PhysRevB.74.174122⟩. ⟨hal-00117311⟩