High-pressure optical floating-zone growth of Li(Mn,Fe)PO${}_4$ single crystals

Abstract

Mm-sized LiMn${}_{1-x}$Fe${}_x$PO${}_4$ single crystals with $0\le x\le 1$ were grown by means of the traveling floating-zone technique at elevated Argon pressure of 30~bar. For the various doping levels, the growth process was optimized with respect to the composition-dependant effective light absorption and transparency of the materials. A convex crystal/melt interface, determined by the angle of incident light, was identified to be particularly crucial for a successful growth. The resulting large single crystalline grains are stoichiometric. Structure refinement shows that lattice parameters as well as the atomic positions and bond lengths linearly depend on the Mn:Fe-ratio. Oriented cuboidal samples with several mm${}^3$ of volume were used for magnetic studies which imply an antiferromagnetic ground state for all compositions. The Néel-temperature changes from $T_N$ = 32.5(5) K in LiMnPO${}_4$ to 49.5(5) K in LiFePO${}_4$ while the easy magnetic axis in the ordered phase flips from the crystallographic $a$- to the $b$-axis upon Fe-doping of $x<0.2$.

References in corpus (1)

• Morphology and agglomeration control of LiMnPO${}_4$ micro- and nanocrystals

Cited by in corpus (4)

• High-pressure optical floating-zone growth of Li2FeSiO4 single crystals
• High-magnetic field phase diagram and failure of magnetic Grüneisen scaling in LiFePO${}_4$
• Challenges in the crystal growth of Li2FeSiO4
• Synthesis and Magnetism of a Li${}_2$FeSiO${}_4$ Single Crystal