Low energy THz excitations in distorted perovskites under strong magnetic fields and low temperature

VINH TA PHUOC,; N. E. MASSA; D. DE SOUSA MENESES; R. SOPRACASE; P. ECHEGUT; K. HOLLDACK; L. DEL CAMPO; . N. E. MASSA, C. PIAMONTEZE, H.C.N. TOLENTINO, J. A. ALONSO, M. J. MARTÍNEZ-LOPE AND M. T. CASAIS.

Baltimore

Congreso; American Physical Society March Meeting; 2016

Anerican Physical Society

We report on the magnetic field evolution of distinctive absorption bands in several zero field cooled polycrystalline RMO3 (R= Pr, Nd, Sm, Er, Tm, Lu; M= Cr, Mn, Fe. Ni) at low temperatures. Measurements below 120 cm−1 were done in an 11 T magnet combined with a Bruker IFS125-HR interferometer at the THz beamline of the BESSY II storage ring. At the reordering spin temperature, the spectra of ErCrO3 show an Er-Kramers doublet at extasciitilde 55 cm−1 following a second order continuous reorientation. It suggests strong anisotropic Er3+-Cr3+magnetic exchange interactions. The band strength of its triplet excited states decreases upon increasing the magnetic field. Non-Kramers Pr in PrCrO3 implies a magnetic field induced quasi-doublet system. Spin wave modes AF and F are also tentatively assigned. In ErFeO3, the spin reordering of the canted transition metal, and the Er3+ exchange, is monitored emerging above 80 K. Temperature dependent multiplet transitions centered at 50 cm−1 and 110 cm−1 appear as asymmetric field dependent broad lines. The absence of activity at extasciitilde 4 K in SmCrO3, shared by SmMO3(M=Fe, Ni), is consequence of near Cr-canted-Rare-Earth-opposite moment compensation juxtaposed to random micrograin orientation. We will also comment on observed only in ErNiO3 field dependent Er transitions and band profiles