2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28916The temperatuer dependence of the magnetic penetration depth of grain aligned YBa2Cu4O8 has been measured along the ab plane and c-axis. Both $λ_ab$ and $λ_c$ vary as \sqrt{T} up to 0.4Tc implying a square root density of states at low energy. The results are discussed in terms of a proximity model of alternating stacked superconducting and normal layers4 pages, 3 figuresSuperconductivitytext