Magnetic and electric properties of triangular lattice antiferromagnets Ba3ATa2O9 (A = Ni and Co). (April 2017)

• Record Type: Journal Article
• Authors: Lee, M.; Choi, E.S.; Ma, J.; Sinclair, R.; Cruz, C.R. Dela; Zhou, H.D.
• Is Part Of: Materials research bulletin. Volume 88(2017)
• Page Start: 308
• Page End: 314
• Publication Date: 2017-04
• Subjects: Geometrical frustration -- Triangular lattice antiferromagnet -- Exotic magnetic ground states -- Multiferroicity; Materials -- Periodicals; Crystal growth -- Periodicals; Matériaux -- Périodiques; Cristaux -- Croissance -- Périodiques; Crystal growth; Materials; Periodicals; 620.11
• DOI: 10.1016/j.materresbull.2016.12.039
• Languages: English
• ISSNs: 0025-5408

Abstract

Abstract : Highlights: Magnetic and electric properties of two triangular lattice antiferromagnets, Ba3 NiTa2 O9 and Ba3 CoTa2 O9 are investigated. Comparison with those sister compounds Ba3 NiNb2 O9 and Ba3 CoNb2 O9 are made. The role of interlayer coupling in determining the physical properties of triangular lattice antiferromagnets are discussed. Abstract: We investigated magnetic and electric properties of two triangular lattice antiferromagnets (TLAFs), Ba3 A Ta2 O9 ( A = Ni and Co). Ba3 NiTa2 O9 shows (i) a single antiferromagnetic phase transition to 120 degree ordered state at T N ∼ 3.3 K, (ii) a weak spin-flop-like transition in isothermal magnetization curves around 4 T, and the saturation magnetization about 1.6 μ B per Ni 2+ above 9.2 T, and (iii) a weak magnetoelectric effect could be removed without ferroelectricity. Comparing to the isostructural TLAF, Ba3 NiNb2 O9 [Phys. Rev. Lett.109, 257205 (2012)], which exhibits successive magnetic phase transitions and ferroelectricity, Ba3 NiTa2 O9 shows lower T N, smaller saturation magnetization, no successive phase transition, and no ferroelectricity. These differences indicate that the higher order superexchange interaction involving Ta atomic orbitals in Ba3 NiTa2 O9 disrupts not only the exotic magnetic phases, also ferroelectricity. We show that this scenario can be also applied to explain the differences between Ba3 CoTa2 O9 and Ba3 CoNb2 O9 [Phys. Rev. B89, 104420 (2014)].