2024/12/26 by Kaitong Sun, Si Wu, Sun, Kaitong +17
Physics and Astronomy · Materials Science · #Rare-earth and actinide compounds #Magnetic Properties of Alloys #Metallurgical and Alloy Processes
paper · pdf · doi:10.48550/arxiv.2412.19181
We present a comprehensive investigation into the physical properties of intermetallic ErPd2Si2, a compound renowned for its intriguing magnetic and electronic characteristics. We confirm the tetragonal crystal structure of ErPd2Si2 within the I4/mmm space group. Notably, we observed anisotropic thermal expansion, with the lattice constant a expanding and c contracting between 15 K and 300 K. This behavior is attributed to lattice vibrations and electronic contributions. Heat capacity measurements revealed three distinct temperature regimes: T1 ∼ 3.0 K, T_\textrmN ∼ 4.20 K, and T2 ∼ 15.31 K. These correspond to the disappearance of spin-density waves, the onset of an incommensurate antiferromagnetic (AFM) structure, and the crystal-field splitting and/or the presence of short-range spin fluctuations, respectively. Remarkably, the AFM phase transition anomaly was observed exclusively in low-field magnetization data (120 Oe) at T_\textrmN. A high magnetic field (B = 3 T) effectively suppressed this anomaly, likely due to spin-flop and spin-flip transitions. Furthermore, the extracted effective PM moments closely matched the expected theoretical value, suggesting a dominant magnetic contribution from localized 4f spins of Er. Additionally, significant differences in resistance (R) values at low temperatures under applied B indicated a magnetoresistance (MR) effect with a minimum value of -4.36%. Notably, the measured MR effect exhibited anisotropic behavior, where changes in the strength or direction of the applied B induced variations in the MR effect. A twofold symmetry of R was discerned at 3 T and 9 T, originating from the orientation of spin moments relative to the applied B. Intriguingly, above T_\textrmN, short-range spin fluctuations also displayed a preferred orientation along the c-axis due to single-ion anisotropy.