Epitaxial Superconducting δ-MoN Films Grown by a Chemical Solution Method

Abstract

The synthesis of pure δ-MoN with desired superconducting properties usually requires extreme conditions, such as high temperature and high pressure, which hinders its fundamental studies and applications. Herein, by using a chemical solution method, epitaxial δ-MoN thin films have been grown on c-cut Al(2)O(3) substrates at a temperature lower than 900 °C and an ambient pressure. The films are phase pure and show a T(c) of 13.0 K with a sharp transition. In addition, the films show a high critical field and excellent current carrying capabilities, which further prove the superior quality of these chemically prepared epitaxial thin films.

Synthesis of nanocrystalline δ-MoN by thermal annealing of amorphous thin films grown on (100) Si by reactive sputtering at room temperature

“…Finally, for comparison with δ-MoN obtained by chemical methods [12,15], the J c (H) dependences at 4.5 K for [100-700] and [170-700] were obtained (see Fig. 7).…”

“…The molybdenum nitrides present several superconducting crystalline phases: γ-Mo 2 N (cubic) with T c ~ 5 K [4], β-Mo 2 N (tetragonal) with superconducting critical temperature T c ~ 5 K [5] and δ-MoN (hexagonal) with T c ~ 13 K [6,7]. Thin films of the different crystalline structures have been sintered through chemical and physical routes [8,9,10,11,12,13]. An outstanding feature for γ-Mo 2 N and δ-MoN is that sharp superconducting transitions have been observed for epitaxial and polycrystalline thin films [14,15,16].…”

Structural, elastic, and thermodynamic properties of hexagonal molybdenum nitrides under high pressure from first principles

“…The measured bulk modulus (345 GPa [9]) is comparable to the 370 GPa of the well-known cubic boron nitride (c-BN) [30] and approximate to the 350 GPa of cubic B 1 -MoN [18][19][20]27]. Kanoun et al [27] have investigated the structure and mechanical stability of d-MoN in 2007.…”

Reflection thermal diffuse x-ray scattering for quantitative determination of phonon dispersion relations

“…In particular, novel metastable phases, inaccessible by bulk synthesis techniques, can be produced using kinetically-limited growth processes [14][15][16][17][18][19][20][21] and epitaxial constraints [22][23][24][25][26][27]. Despite the importance of thin films, there are only a restricted number of methods [28,29] for determining phonon dispersion relations for this class of materials.…”