High-pressure synthesis, crystal structures, and magnetic and dielectric properties of GdFeO3-type perovskites (Dy0.5Mn0.5)(Mn1−Ti )O3 with x = 0.5 and 0.75

(Ca0.5Mn0.5)2MnTeO6 – An Anomalously Stable High‐Pressure Double Perovskite

“…This DDPv family and other cation‐ordered A ‐site manganites such as Mn 3 MnNb 2 O 9 [22] with 1 : 2 B ‐site ordering have recently been reviewed [4] . Some attempts to prepare HPHT A Mn BB’ O 6 compositions without a high charge difference between B and B’ cations have led to simple disordered perovskites, such as ‘CaMnMnTaO 6 ’ and'DyMnMnTiO 6 ’ which respectively gave GeFeO 3 ‐type Pnma (Ca 0.5 Mn 0.5 )(Mn 0.5 Ta 0.5 )O 3 and (Dy 0.5 Mn 0.5 ) (Mn 0.5 Ti 0.5 )O 3 perovskites without A ‐ or B ‐site cation orders [23,24] …”

“…[4] Some attempts to prepare HPHT AMnBB'O 6 compositions without a high charge difference between B and B' cations have led to simple disordered perovskites, such as 'CaMnMnTaO 6 ' and'DyMnMnTiO 6 ' which respectively gave GeFeO 3 -type Pnma (Ca 0.5 Mn 0.5 )(Mn 0.5 Ta 0.5 )O 3 and (Dy 0.5 Mn 0.5 ) (Mn 0.5 Ti 0.5 )O 3 perovskites without A-or B-site cation orders. [23,24] A further interesting aspect is that some apparent AMnBB'O 6 double double perovskite compositions are found to adopt double perovskite structures, written as (A 0.5 Mn 0.5 ) 2 BB'O 6 to show that the A and Mn 2 + cations are disordered over perovskite A-sites while B/B' retain rocksalt type long-range order. This was first discovered in the RMnMnSbO 6 series where materials with R in the range La-Sm were found to form the DDPv structure with columnar R/Mn A-site order, whereas for Eu and later R the (A 0.5 Mn 0.5 ) 2 BB'O 6 DPv with disordered A-site R/Mn was formed.…”