The nano-microfibrous R11Ni4In9 intermetallics: New compounds and extraordinary anisotropy in Tb11Ni4In9 and Dy11Ni4In9. (1st June 2015)

• Record Type: Journal Article
• Authors: Provino, A.; Gschneidner, K.A.; Dhar, S.K.; Ferdeghini, C.; Mudryk, Y.; Manfrinetti, P.; Paudyal, D.; Pecharsky, V.K.
• Is Part Of: Acta materialia. Volume 91(2015)
• Page Start: 128
• Page End: 140
• Publication Date: 2015-06-01
• Subjects: Rare earth intermetallics -- Nanowires -- Magnetic shape anisotropy -- Fiber compounds -- Ferrimagnetic ordering; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2015.03.003
• Languages: English
• ISSNs: 1359-6454

Abstract

Graphical abstract: Abstract: R11 Ni4 In9 (R = rare earth) compounds exhibit an unusual self-assembled nano/microfibrous morphology that results in anisotropic structural and magnetic behaviors. The existence of new compounds for R = Dy, Ho, Er, Tm and Lu, has been established (orthorhombic Nd11 Pd4 In9 -type, oC 48, Cmmm, Z = 2), showing that the formation of these phases, previously known for R = La–Nd, Sm, Gd, Tb and Y, extends to all of the rare earth elements, except Sc, Eu and Yb. The results of physical property measurements performed on oriented fibers of Tb11 Ni4 In9, Dy11 Ni4 In9 and Y11 Ni4 In9 are presented. Multiple magnetic transitions are observed in Tb11 Ni4 In9 and Dy11 Ni4 In9 with the highest ordering temperature, T C, of 112 and 88 K, respectively. Y11 Ni4 In9 is a Pauli paramagnet down to 2 K. The fibrous microstructure of these compounds leads to a strong anisotropy in their electrical resistivity and magnetization behaviors. The c -axis of the orthorhombic cell is the easy magnetization and high electrical-conductivity direction. Ferrimagnetic-like behavior, with extremely high coercive fields ( H C = 6.6 T for Tb11 Ni4 In9 at 5 K and H C = 5.7 T for Dy11 Ni4 In9 at 2 K), is found when the fibers (and the c -axis) are oriented parallel to the magnetic field direction; antiferromagnetic-like ground state is observed with the fibers oriented orthogonal ( i.e., in the a–b plane). Appearance of a Griffiths phase regime is observed in both compounds before entering the ordered magnetic states. This is more evident for fibers orthogonal to the magnetic field and is even preserved at 1 T. Field induced spin-flop magnetic transitions are also observed in Tb11 Ni4 In9 and Dy11 Ni4 In9 with fibers orthogonal and parallel to the field, respectively. First principles calculations have been performed for several representative compounds to explain the underlying phase stability and their magnetism.