Condensed-Matter Physics & Materials Science Seminar

The search for fascinating materials with interesting electronic and magnetic properties has led to an enormous development in diverse areas of condensed matters physics. In particular, the Indium-rich materials containing rare-earth elements can host exotic physical phenomena emerging from the competition and/or cooperation of several physical mechanisms such as the Ruderman-Kittel-Kasuya-Yosida (RKKY) magnetic interaction, heavy fermion (HF) behavior, crystalline electric field (CEF) and Kondo effects[1,2].Since the magnetic ordering and the screening of f-electrons have an important role in the ground state properties of these materials, the magnetic structure determination can be a powerful tool to understand how the moments of the magnetic ions are interacting among each other. In this sense, x-ray resonant magnetic scattering (XRMS) technique was employed to solve the magnetic structure at low temperature of the new intermetallic EuPtIn4 compound. At the resonant energy of the Eu ion (7617 eV – L2 edge), magnetic incommensurate (ICM) reflections with propagation vector type (1/2, 1/2, τ) with τ ~ 0.427 were observed. Temperature and magnetic field dependence performed at the magnetic reflections reveal an AFM coupling with a Néel temperature TN = 13.1 K and a spin flop transition above 3 T, respectively. In addition, we do not observe any magnetic anomalies related to a second phase transition as suggested in the previously reported macroscopic measurements [3,4]. The ICM phase observed at low temperature is due to geometric frustration of the Eu ions in which the RKKY exchange interaction cannot be simultaneously satisfied. Although the EuPtIn4 compound displays similar properties to a heavy fermion compound such as exotic magnetic structure and enhancement of Sommerfeld coefficient, further investigation must be performed in this new series of materials.[1] Z. Fisk, et al., Proc. Natl. Acad. Sci. USA 92, 6663 (1995).[2] P. Coleman, Handb