μSR investigation of magnetically ordered states in theA-site ordered perovskite manganitesRBaMn2

Abstract

The magnetically ordered states of the A-site ordered perovskite manganites LaBaMn2O6 and YBaMn2O6 have been investigated by muon spin relaxation in zero external magnetic field. Our data reveal striking differences in the nature of the magnetically ordered state between these materials. For LaBaMn2O6, the µSR time-spectra in the ferromagnetic state below ≃ 330 K reveal a strongly inhomogeneous phase, reminiscent of a Griffiths phase. Within this magnetically inhomogeneous phase, an antiferromagnetic state develops below 150 K, which displays well defined static internal magnetic fields, but reaches only 30% of the volume fraction at low temperatures. A broad distribution of µSR relaxation rates is inferred down to the lowest temperatures. This behavior is similar to that in the A-site disordered La0.5Ba0.5MnO3. On the other hand, for YBaMn2O6, the µSR time spectra for both (i) the charge and orbital ordered and (ii) the paramagnetic phases reveal rather homogeneous states, namely, an exponential relaxation in the paramagnetic state and well defined muon spin oscillation in the antiferromagnetic state.

Magnetic states of Ni-Mn-Sn based shape memory alloy: A combined muon spin relaxation and neutron diffraction study

“…Here b g denotes the time independent background of asymmetry. Similar two exponent model has been used for diverse magnetic systems successfully, which include perovskite manganites, [29][30][31] cobaltates, 32 , as well as Hesuler based intermetallic alloys. 33 Muons, whose nearest atom on the Z sublattice is either Mn ′ or Sn, are subject to different internal fields.…”

A-Site Ordered Double Perovskite with in Situ Exsolved Core–Shell Nanoparticles as Anode for Solid Oxide Fuel Cells

“…A-site ordered double-perovskites LnBaMn2O5+δ (Ln means lanthanides such as Pr, Nd and Sm) and their derivatives have been widely investigated as ferromagnetic materials. 32,33 In the last few years, they have attracted attention as fuel electrodes of SOFCs and solid oxide electrolyzer cells due to their high oxygen ionic diffusion rate and high electronic conductivity. [34][35][36][37][38][39][40][41][42][43]…”

“…A-site ordered double-perovskites LnBaMn 2 O 5+δ (Ln means lanthanides such as Pr, Nd, and Sm) and their derivatives have been widely investigated as ferromagnetic materials. , In the past few years, they have attracted attention as fuel electrodes of SOFCs and solid oxide electrolyzer cells due to their high oxygen ionic diffusion rate and high electronic conductivity. − A layered structure [LnO δ ]–[MnO 2 ]–[BaO]–[MnO 2 ]–[LnO δ ] along the c axis is formed accompanied by the loss of lattice oxygens during the reduction. The oxygen vacancies formed in the [LnO δ ] planes facilitate the electrochemical oxidation of fuels and provide two-dimensional channels for the fast conduction of oxygen ions. ,,, A 300 μm thick La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ electrolyte-supported single cell with PrBaMn 2 O 5+δ (PBM) as the anode obtained a P max of 0.57 W cm –2 at 850 °C using H 2 as fuel.…”