Spin reorientation and disordered rare earth magnetism in Ho₂FeCoO₆

Abstract

Abstract. We report the experimental observation of spin reorientation in the double perovskite Ho 2 FeCoO 6 . The magnetic phase transitions in this compound are characterized and studied through magnetization and specific heat, and the magnetic structures are elucidated through neutron powder diffraction. Two magnetic phase transitions are observed in this compound -one at T N1 ≈ 250 K, from paramagnetic to antiferromagnetic, and the other at T N2 ≈ 45 K, from a phase with mixed magnetic structures to a single phase through a spin reorientation process. The magnetic structure in the temperature range 200 K -45 K is a mixed phase of the irreducible representations Γ 1 and Γ 3 , both of which are antiferromagnetic. The phase with mixed magnetic structures that exists in Ho 2 FeCoO 6 gives rise to a large thermal hysteresis in magnetization that extends from 200 K down to the spin reorientation temperature. At T N2 , the magnetic structure transforms to Γ 1 . Though long-range magnetic order is established in the transition metal lattice, it is seen that only short-range magnetic order prevails in Ho 3+ -lattice. Our results should motivate further detailed studies on single crystals in order to explore spin reorientation process, spin switching and the possibility of anisotropic magnetic interactions giving rise to electric polarization in Ho 2 FeCoO 6 .

Extraordinary magnetic properties of double perovskite Eu2CoMnO6 wide band gap semiconductor

“…The materials with such extraordinary, multi-functional properties are gained much more interest due to their attractive, well-to-do physics and panorama for technological device applications [2][3][4]. In the last few decades, people are trying to search for such new multifunctional materials for next-generation spintronic devices [4][5][6][7][8][9][10][11][12][13]. In this regard, the rare earth double perovskite (DP) oxides, A 2 BB O 6 (A = rare earth ions or alkaline ions; B/B = transition metal ions) with rock salt ordered structure are of great importance for their multi-functional properties.…”

Microscopic insights of magnetism in Sm$ _{2} $NiMnO$ _{6} $ double perovskite

“…On further decrease of temperature at T∼T d intensity of feature B encounters a downturn whereas intensity of A increases. In a previous study [43], cation disordered (Pbnm symmetry) Ho 2 FeCoO 6 double perovskite is found to show significant intensity redistribution in magnetic Bragg's lines at low temperature, which is identified as spin reorientation transition leading to transformation from mixed magnetic structure to single magnetic structure. However, this is not the case for SNMO system, as here single magnetic structure is evidenced for all temperature values below T=T C (discussed later).…”

Roles of Re-entrant cluster glass state and spin–lattice coupling in magneto–dielectric behavior of giant dielectric double perovskite La1.8Pr0.2CoFeO6

“…The strong coupling between magnetic and electrical ordering is one of the key issues to realize the multifunctional materials for potential applications [1][2][3][4]. In this regard, double perovskites (DP) A 2 BB O 6 (where A is rare earth or alkaline ions, B/B are transition metal ions) with rock salt ordered structure [5] are forming the promising classes of multifunctional materials which exhibit unique physical properties such as near room temperature ferromagnetic insulating ground state, large magneto-dielectric effect (MDE), Griffiths phase, giant exchange bias, low temperature re-entrant glassy states, spin-phonon coupling etc [6][7][8][9][10][11][12][13]. Recently, A 2 CoFeO 6 types 4 Author to whom any correspondence should be addressed.…”

“…of DP oxides have gained attention due to their high temperature phase transitions [10]. In fact, Co and Fe ions have their own features as they have similar size and valance states.…”

“…In fact, Co and Fe ions have their own features as they have similar size and valance states. So far, very limited number of studies have been reported on the DP oxides with Co-Fe combination for different rare earth ions and alkaline ions (A = Pr, La, Ho, Sr) [10][11][12][13]. Moreover, among multifunctional material properties, magneto-dielectric effect (MDE) is one of the most fascinating and auspicious characteristics in both scientific and technological aspects [14,15].…”