Resumen: The magnetic lanthanide (Ln3+) ions in the fergusonite and scheelite crystal structures form a distorted or stretched diamond lattice which is predicted to host exotic magnetic ground states. In this study, polycrystalline samples of the fergusonite orthotantalates M-LnTaO4 (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er) were synthesized and then characterized using powder diffraction and bulk magnetometry and heat capacity. TbTaO4 orders antiferromagnetically at 2.25 K into a commensurate magnetic cell with k =0, magnetic space group 14.77 (P21'/c), and Tb moments parallel to the a axis. No magnetic order was observed in the other materials studied, leaving open the possibility of exotic magnetic states at T<2 K. Idioma: Inglés DOI: 10.1103/PhysRevMaterials.6.044410 Año: 2022 Publicado en: PHYSICAL REVIEW MATERIALS 6, 4 (2022), 044410 [11 pp.] ISSN: 2475-9953 Factor impacto JCR: 3.4 (2022) Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 174 / 343 = 0.507 (2022) - Q3 - T2 Factor impacto CITESCORE: 6.4 - Physics and Astronomy (Q1) - Materials Science (Q2)