Breaking the geometric magnetic frustration in controlled off-stoichiometric LuMn1+zO3+d compounds.

Physical chemistry chemical physics : PCCP

PubMedID: 27140064

Figueiras FG, Karpinsky D, Tavares PB, Das S, Leitão JV, Brück EH, Moreira JA, Amaral VS. Breaking the geometric magnetic frustration in controlled off-stoichiometric LuMn1+zO3+d compounds. Phys Chem Chem Phys. 2016;.
This study explores controlled off-stoichiometric LuMn1+zO3+d (|z| < 0. 1) compounds, intended to retain the utter LuMnO3 intrinsic hexagonal symmetry and ferroelectric properties. X-ray powder diffraction measurements evidenced a single phase P63cm structure. Thermo-gravimetric experiments show a narrow impact of oxygen vacancies while a distinguishable gas exchange at ~700 K, a surprisingly lower temperature when compared to perovskite systems. A comparison of different nominal ceramics revealed pertinent structural and magnetic property variations owing to subtle self-doping effects. Deviations from the archetypal antiferromagnetic state were detected below ~90 K suggesting local rearrangements of the nominal Mn(3+) ions matrix, breaking the ideal geometrical spin frustration, leading to a non-compensated magnetic structure.