Seminarium Oddziału Badań Magnetyków
sala 6 bud. II
Anomalous magnetic properties of rare-earth based Th3P4-type noncentrosymmteric lattices
dr Prabuddha Kant Mishra
INTiBS PAN
This study unravels competing magnetic interactions and field-induced phenomena in noncentrosymmetric Nd₃X₄ (X= Se and Te), a rare-earth chalcogenide with a Th₃P₄-type cubic structure (I-43d space group). Synthesized via solid-state methods, these materials exhibit anamolous magnetic phenomena driven by competing symmetric and antisymmetric (Dzyaloshinskii-Moriya, DMI) exchange interactions. Key findings from dc/ac magnetization, magnetocaloric, and magnetotransport studies are:
1. A first-order magnetic transition at Tc ≈ 37 K (Nd3Te4) Tc ≈52 K (Nd3Se4), accompanied by large ZFC-FC irreversibility and negative magnetization at low fields (<1 kOe), signifies the coexistence of ferromagnetic and antiferromagnetic interactions.2. Asymmetric exchange interactions manifest as noncollinear spin textures, consistent with nonsaturating magnetization upto applied field of 70 kOe.
3. Competing interactions enhance the magnetoentropy change (-ΔSm ≈ 4.5 J/kg·K at 5 T), with an inverse magnetocaloric effect at low applied fields, observed near Tc.
4. Estimation of critical field, below which there is observation of field cooled negative magnetization and kink in ac-susceptibility as function of field.
5. Significant negative magnetoresistance and a large Sommerfeld coefficient suggest strong electron correlations.
These results establish Th₃P₄ lattice as a model system for probing DMI-driven phenomena in noncentrosymmetric lattices, with implications for spintronic memory and magnetic refrigeration technologies. The work bridges structural asymmetry, competing exchange interactions, and emergent quantum states in rare-earth chalcogenides.
References
1. Mishra et al., Phys. Scr. 99, (9) 095985 (2024).2. Mishra et al., Chem. Mater. 36, (12) 5986-5995 (2024).
3. Mishra et al., J. Solid State Chem. Mater. 36, (12) 124647 (2024).
4. Magnetic, magnetocaloric and specific heat studies of Nd3Se4., J. Mag. Mag. Mater. (submitted).
