10.1016/j.jssc.2009.11.025
Crystal growth, structure and magnetic properties of the double perovskites Ln2MgIrO6 (Ln=Pr, Nd, Sm-Gd)

For all compounds, the lanthanide sesquioxides, Ln2O3 (Nd, Sm, Eu, Gd), (Alfa Aesar, 99.99%) were fired at 1000 degC for 12 h prior to the reactions. Pr6O11 (Alfa Aesar, 99.9%) was converted to Pr2O3 by heating Pr6O11 at 1000 degC for 24 h under a reducing 5% H2 atmosphere. KOH (Fisher Scientific, A.C.S Reagent Grade, 99.9%), iridium powder (Engelhard, 99.99%) and MgO (Alfa Aesar, 99.998%) were used as received. Single crystals of Ln2MgIrO6 were grown from a high temperature melt of potassium hydroxide. Ln2O3 (Pr, Nd, Sm, Eu, Gd) (0.5 mmol), MgO (1 mmol), Ir (0.5 mmol), and KOH (4 g) were loaded into sealed silver tubes and heated in a box furnace to a temperature of 700 degC at 10 degC/min, held for 24 h at 700 degC, slow cooled to 600 degC at 0.2 degC/min and then allowed to cool to room temperature by turning off the furnace. The black crystals were removed from the flux matrix by dissolving the flux in water aided by sonication. The crystals were finally extracted by vacuum filtration.
Ln2O3
99.99%
%
Ln2O3
fired
1000 degC
degC
Ln2O3
fired
12 h
h
Pr6O11
99.9%
%
Pr6O11
heating
1000 degC
degC
Pr6O11
heating
24 h
h
atmosphere
H2
5%
%
KOH
99.9%
%
iridium powder
99.99%
%
MgO
99.998%
%
Ln2O3 (Pr, Nd, Sm, Eu, Gd) (0.5 mmol), MgO (1 mmol), Ir (0.5 mmol), and KOH (4 g) were loaded into sealed silver tubes
heated
700 degC at 10 degC/min, held for 24 h at 700 degC
degC
Ln2O3 (Pr, Nd, Sm, Eu, Gd) (0.5 mmol), MgO (1 mmol), Ir (0.5 mmol), and KOH (4 g) were loaded into sealed silver tubes
heated
24 h
h
Ln2O3 (Pr, Nd, Sm, Eu, Gd) (0.5 mmol), MgO (1 mmol), Ir (0.5 mmol), and KOH (4 g) were loaded into sealed silver tubes
cooled
0.2 degC/min
degC/min
KOH
loaded into sealed silver tubes
4 g
g
MgO
loaded into sealed silver tubes
1 mmol
mmol
Ln2O3 (Pr, Nd, Sm, Eu, Gd) (0.5 mmol), MgO (1 mmol), Ir (0.5 mmol), and KOH (4 g) were loaded into sealed silver tubes
heated
10 degC/min
degC/min
Ln2O3 (Pr, Nd, Sm, Eu, Gd) (0.5 mmol), MgO (1 mmol), Ir (0.5 mmol), and KOH (4 g) were loaded into sealed silver tubes
cooled
600 degC
degC
Ir
loaded into sealed silver tubes
0.5 mmol
mmol
Ln2O3
loaded into sealed silver tubes
0.5 mmol
mmol