Proving existence of vibronic state in CeCuAl3 (p13907)

Our recent systematic research on CeCuAl3 and Cu-Al substituted compounds has brought many important results on their physical properties, namely peculiar magnetic excitations. CeCuAl3 crystallizes in the tetragonal BaNiSn3-type structure (space group I4mm, 107) and orders antiferromagnetically with Néel temperature 2.7 K. CeCuAl3 shows interesting magnetic behavior which is discussed as a result of interplay between the magnetic RKKY and Kondo interactions and the influence of the low lying excited crystal field (CF) state. The amplitude modulated magnetic structure is described by the propagation vector (0.4, 0.6, 0) and magnetic moments arranged within the tetragonal plane. CeCuAl3 belongs among a few cerium compounds where the strong CF excitation-phonon coupling resulting in new quasi-bound states, vibrons, was proposed. Our very recent single crystal experiments using ThALES and IN20 spectrometers proved the presence of 3 magnetic (crystal field) peaks in energy spectrum of CeCuAl3.
The aim of proposed experiment is to investigate the evolution of structure parameters and magnetic excitations with uniaxial pressure, which will give us substantial information on microscopic mechanism responsible for additional (vibron) excitation. TRISP and PUMA instruments are natural choice for this study.Instruments:
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