4. Conclusion

Just over three years after the discovery of superconductivity in LaFeAsO _1-x F _x , it's still too early to predict whether iron-based superconductors will see significant technological applications. While the high value of their critical field and their significantly lower anisotropy than that of cuprates should open up fields of application for them in the form of thin films, the low critical current densities observed in polycrystalline wires, probably due to intergranular weak bonds, should undoubtedly limit their potential for high-current applications. On a more fundamental level, many questions remain unanswered as to the origin of the superconducting state, the symmetry of the order parameter... Nevertheless, the unexpected nature of their discovery – in an iron-based material, the usual poison...