NMR Spectroscopy on Heusler Thin Films - A Review

Heusler compounds exhibit different electronic ground states and functionalities, making them attractive materials for studies of their fundamental properties and for their technological exploitation. The high spin polarization, predicted in particular for Co2-based Heusler compounds, renders them prime candidates for electrode materials in spintronic devices such as giant magnetoresistance (GMR) elements or magnetic tunnel junctions and requires their implementation in thin film stacks. The growth of high quality Heusler films, however, demands their careful characterization. Typical issues in Heusler thin films are, besides the type and degree of structural order, the control of the film composition and the conservation of smooth interfaces between different layers in the film, e.g., between the Heusler layer and the tunneling barrier, while at the same time enabling high structural order. This review illustrates how nuclear magnetic resonance spectroscopy contributes to those issues by discussing recent examples of nuclear magnetic resonance studies of Heusler thin films.