Carrier-induced magnetic phase transition in Cd1?x MnxTequantum wells with high Mn content

摘要

We present a study of the susceptibility and magnetization in the paramagnetic and orderedphases of Cd1?x MnxTe quantum wells with a hole gas. The hole gas was created using surfacestates. This allowed us to increase the Mn content to 9.3% (previously reported values neverexceeded 5% for nitrogen doped samples) while the hole gas density was still large enoughto observe the magnetic transition. In samples with a higher Mn content, we observe a clearincrease of the phase transition temperature, which becomes definitely higher than the Curie-Weiss temperature - an effect we tentatively ascribe to increased disorder.