Infrared phonons and specific heat in Ba3Cr2O8

Abstract

We report on the phonon spectrum of Ba3Cr2O8 determined by infrared spectroscopy, and on specific heat measurements across the Jahn-Teller transition in magnetic fields up to 9 T. Phonon modes split below the Jahn-Teller transition, which occurs at T_{JT} = 70 K as detected by specific heat measurements. The field-dependent specific heat data is analyzed in terms of the contributions from lattice, magnetic and orbital degrees of freedom. In contrast to the isostructural compound Sr3Cr2O8 our analysis does not indicate the existence of orbital fluctuations below the Jahn-Teller transition in Ba3Cr2O8.

5 pages, 4 figures

References in corpus (15)

• Bose-Einstein Condensation in Magnetic Insulators
• Magnetic light scattering in low-dimensional quantum spin systems
• Field-induced Bose-Einstein Condensation of triplons up to 8 K in Sr3Cr2O8
• Bose-Einstein Condensation of Triplons in Ba3Cr2O8
• Structural and magnetic dimers in the spin-gapped system CuTe2O5
• Magnetic excitations of the gapped quantum spin dimer antiferromagnet Sr${}_3$Cr${}_2$O${}_8$
• Asymmetric quintuplet condensation in the frustrated S=1 spin dimer compound Ba3Mn2O8
• Weakly coupled $s=1/2$ quantum spin singlets in Ba${}_3$Cr${}_2$O${}_8$
• Spin dynamics in the low-dimensional magnet TiOCl
• Dispersive magnetic excitations in the S=1 antiferromagnet Ba${}_3$Mn${}_2$O${}_8$
• Orbital fluctuations and orbital order below the Jahn-Teller transition in Sr3Cr2O8
• Singlet-triplet excitations and high-field magnetization in CuTe2O5
• Magnetization and specific heat of the dimer system CuTe2O5
• Coupled spin-lattice fluctuations in a compound with orbital degrees of freedom: the Cr based dimer system Sr3Cr2O8
• Theory of Magnetic Field-Induced Bose-Einstein Condensation of Triplons in Ba3Cr2O8

Cited by in corpus (7)

• FeCr${}_2$S${}_4$ in magnetic fields: possible evidence for a multiferroic ground state
• High-field spectroscopy of singlet-triplet transitions in the spin-dimer systems Sr3Cr2O8 and Ba3Cr2O8
• Gr{ü}neisen parameter of quantum magnets with spin gap
• Structural and magnetic properties in the quantum S=1/2 dimer systems Ba3(Cr1-xVx)2O8 with site disorder
• Neutron diffraction of field-induced magnon condensation in the spin-dimerized antiferromagnet Sr${}_3$Cr${}_2$O${}_8$
• Anomalous magnetic exchange in a dimerized quantum-magnet composed of unlike spin species
• Tuning the orbital-lattice fluctuations in the mixed spin-dimer system Ba${}_{3-x}$Sr${}_x$Cr${}_2$O${}_8$