Berlin 2018 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 52: Poster II

MA 52.70: Poster

Donnerstag, 15. März 2018, 15:00–18:00, Poster C

Single crystal growth, magnetic phase diagram and antiferromagnetic resonance modes in MTiO₃ (M=Co,Ni) — •Kaustav Dey¹, Johannes Werner¹, Jakob Kaiser¹, Changhyun Koo¹, Rabrindranath Bay², Surjeet Singh², and Rüdiger Klingeler¹ — ¹Kirchhoff Institute for Physics, Heidelberg University, Germany — ²Indian Institute of Science Education and Research (IISER), Pune, India

Single crystals of layered S=1 and S=3/2 antiferromagnets MTiO₃ (M=Co,Ni) which both show pronounced magnetodielectric coupling have been grown by the optical floating-zone method. The single crystals have been studied by means of magnetometry up to 60 T and high-frequency electron spin resonance (HF-ESR). The magnetic phase diagrams are derived, including a broad field-induced anomaly indicative of spin-reorientation for B||ab-plane. For NiTiO₃, the reonance frequency vs. field diagram in the ordered state and the temperature dependence of the main resonance modes are presented. The antiferromagnetic resonance modes imply an easy plane-type anisotropy. Zero-field splitting of the out-of-plane modes amounts to 190 GHz and the gapped in-plane mode is consistent with the saturation field of B_ab=35 T seen in the pulsed-field magnetisation studies. In CoTiO₃, the HF-ESR data are less clear but there is evidence for the easy-plane mode saturating at B_ab=16 T with zero-field splitting well beyond the accessible frequency range of 1 THz.