J Khatua1,2,3, T Arh4,5, Shashi B Mishra6, H Luetkens7, A Zorko8,9, B Sana1, M S Ramachandra Rao10,2, B R K Nanda11,12,13, P Khuntia14,15,16. 1. Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India. 2. Quantum Centre for Diamond and Emergent Materials, Indian Institute of Technology Madras, Chennai, 600036, India. 3. Functional Oxide Research Group, Indian Institute of Technology Madras, Chennai, 600036, India. 4. Jožef Stefan Institute, Jamova c. 39, 1000, Ljubljana, Slovenia. 5. Faculty of Mathematics and Physics, University of Ljubljana, Jadranska u. 19, 1000, Ljubljana, Slovenia. 6. Condensed Matter Theory and Computational Lab, Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India. 7. Laboratory for Muon-Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen, Switzerland. 8. Jožef Stefan Institute, Jamova c. 39, 1000, Ljubljana, Slovenia. andrej.zorko@ijs.si. 9. Faculty of Mathematics and Physics, University of Ljubljana, Jadranska u. 19, 1000, Ljubljana, Slovenia. andrej.zorko@ijs.si. 10. Department of Physics, Nano Functional Materials Technology Centre and Materials Science Research Centre, Indian Institute of Technology Madras, Chennai, 600036, India. 11. Condensed Matter Theory and Computational Lab, Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India. nandab@iitm.ac.in. 12. Functional Oxide Research Group, Indian Institute of Technology Madras, Chennai, 600036, India. nandab@iitm.ac.in. 13. Atomistic Modelling and Materials Design Group, Indian Institute of Technology Madras, Chennai, 600036, India. nandab@iitm.ac.in. 14. Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India. pkhuntia@iitm.ac.in. 15. Quantum Centre for Diamond and Emergent Materials, Indian Institute of Technology Madras, Chennai, 600036, India. pkhuntia@iitm.ac.in. 16. Functional Oxide Research Group, Indian Institute of Technology Madras, Chennai, 600036, India. pkhuntia@iitm.ac.in.
Abstract
Frustrated magnets based on oxide double perovskites offer a viable ground wherein competing magnetic interactions, macroscopic ground state degeneracy and complex interplay between emergent degrees of freedom can lead to correlated quantum phenomena with exotic excitations highly relevant for potential technological applications. By local-probe muon spin relaxation ([Formula: see text]SR) and complementary thermodynamic measurements accompanied by first-principles calculations, we here demonstrate novel electronic structure and magnetic phases of Ba[Formula: see text]MnTeO[Formula: see text], where Mn[Formula: see text] ions with S = 5/2 spins constitute a perfect triangular lattice. Magnetization results evidence the presence of strong antiferromagnetic interactions between Mn[Formula: see text] spins and a phase transition at [Formula: see text] = 20 K. Below [Formula: see text], the specific heat data show antiferromagnetic magnon excitations with a gap of 1.4 K, which is due to magnetic anisotropy. [Formula: see text]SR reveals the presence of static internal fields in the ordered state and short-range spin correlations high above [Formula: see text]. It further unveils critical slowing-down of spin dynamics at [Formula: see text] and the persistence of spin dynamics even in the magnetically ordered state. Theoretical studies infer that Heisenberg interactions govern the inter- and intra-layer spin-frustration in this compound. Our results establish that the combined effect of a weak third-nearest-neighbour ferromagnetic inter-layer interaction (owing to double-exchange) and intra-layer interactions stabilizes a three-dimensional magnetic ordering in this frustrated magnet.
Frustratepan class="Chemical">d magnets based on oxidedouble perovskites offer a viable ground wherein competing magnetic interactions, macroscopic ground statedegeneracy and complex interplay between emergent degrees of freedom can lead to correlated quantum phenomena with exotic excitations highly relevant for potential technological applications. By local-probe muon spin relaxation ([Formula: see text]SR) and complementary thermodynamic measurements accompanied by first-principles calculations, we here demonstrate novel electronic structure and magnetic phases of Ba[Formula: see text]MnTeO[Formula: see text], where Mn[Formula: see text] ions with S = 5/2 spins constitute a perfect triangular lattice. Magnetization results evidence the presence of strong antiferromagnetic interactions between Mn[Formula: see text] spins and a phase transition at [Formula: see text] = 20 K. Below [Formula: see text], the specific heat data show antiferromagnetic magnon excitations with a gap of 1.4 K, which is due to magnetic anisotropy. [Formula: see text]SR reveals the presence of static internal fields in the ordered state and short-range spin correlations high above [Formula: see text]. It further unveils critical slowing-down of spin dynamics at [Formula: see text] and the persistence of spin dynamics even in the magnetically ordered state. Theoretical studies infer that Heisenberg interactions govern the inter- and intra-layer spin-frustration in this compound. Our results establish that the combined effect of a weak third-nearest-neighbour ferromagnetic inter-layer interaction (owing to double-exchange) and intra-layer interactions stabilizes a three-dimensional magnetic ordering in this frustrated magnet.
Authors: M Kenzelmann; G Lawes; A B Harris; G Gasparovic; C Broholm; A P Ramirez; G A Jorge; M Jaime; S Park; Q Huang; A Ya Shapiro; L A Demianets Journal: Phys Rev Lett Date: 2007-06-29 Impact factor: 9.161
Authors: H D Zhou; Cenke Xu; A M Hallas; H J Silverstein; C R Wiebe; I Umegaki; J Q Yan; T P Murphy; J-H Park; Y Qiu; J R D Copley; J S Gardner; Y Takano Journal: Phys Rev Lett Date: 2012-12-26 Impact factor: 9.161