Rare-earth manganese
pyrochlores (R2Mn2O7) are frustrated
magnetic materials, which previously have
only been accessed using expensive high-pressure and high-temperature
synthesis. In the present work, we demonstrate a convenient synthetic
approach to synthesize R2Mn2O7pyrochlores
at ambient pressure. A series of pyrochlores (R = Y, Ho–Lu)
were prepared by a simple and cost-effective molten salt method using
NaCl and KCl as the flux. Moreover, phase-selectivity was demonstrated
for yttrium manganese oxides (YMnO3and Y2Mn2O7) by a simple variation of synthesis temperature
and precursors-to-chlorides ratio. The synthetic procedure does not
require high pressures or temperatures nor oxygen flow. All synthesized
pyrochlores demonstrated ferromagnetic behavior at low temperature,
and the magnetic properties were in good agreement with those of high-pressure-synthesized
materials. The versatility of the method was confirmed by the preparation
of a mixed-rare earth Y0.4Er0.4Tm0.4Yb0.4Lu0.4Mn2O7solid
solution—a compositionally complex high-entropy oxide.