Growth and Characterization of Centimeter‐Sized Ba 2 LaFeNb 4 O 15 Crystals from High‐Temperature Solution under a Controlled Atmosphere

Centimeter‐sized single crystals of Ba 2 LaFeNb 4 O 15 were grown from a high‐temperature solution by using LiBO 2 flux and a sealed platinum assembly. The obtained single crystals display the same physical properties as their ceramic counterparts. A frequency‐dependent dielectric permittivity maximum was found ( T m = 100 K at 5 kHz), which indicates relaxor behavior. Magnetic susceptibility measurements revealed purely paramagnetic behavior between 10 and 350 K. X‐ray diffraction measurements of Ba 2 LaFeNb 4 O 15 single crystals revealed an incommensurate structure at room temperature with a bidimensional modulation characterized by vectors q 1 = ( α , α , 1/2) and q 2 = ( α , – α , 1/2) with α = 0.295(1). This crystal growth method offers a promising elaboration route to centimeter‐sized crystals of niobate‐based compounds, which may not be grown from the pure liquid phase, especially those with a tetragonal tungsten bronze (TTB) structure.