We present the magnetic and superconducting phase diagram of EuFe 2As2 for Bc and Bab. The antiferromagnetic phase of the Eu2+ moments is completely enclosed in the superconducting phase. The upper critical field vs. temperature curves exhibit strong concave curvatures, which can be explained by the Jaccarino-Peter compensation effect due to the antiferromagnetic exchange interaction between the Eu2+ moments and conduction electrons.
- Iron pnictides
- Pressure-induced superconductivity