Critical region phase transitions in the quasi-2D magnet CrCl3

• DOI: 10.1063/1.5080131
• Publication Date: 2019-03-18T16:23:32Z
• Authors: N. Bykovetz; A. Hoser; C. L. Lin
• Keywords: Physics; QC1-999; 0103 physical sciences; Large scale facilities for research with photons neutrons and ions; 01 natural sciences

CrCl3 has been known for a long time to be quasi-2D ferromagnet (FM) with specific-heat peak at 16.8K. Its 3D ordering is antiferromagnetic (AFM) alternating 2D FM sheets perpendicular the c-axis. Kuhlow [Phys. Stat. Sol. A 72, 161 (1982)] carried out Faraday rotation measurements on and concluded, fairly tenuous grounds, that there are actually two closely spaced magnetic transitions, one “16.7K” which of in-plane spins start ordering, but do so random alignment relative c-axis (the latter being sheets), in AFM takes place, TN ∼15.5K. We have an extensive series precision SQUID magnetometer as function temperature, from very low fields (≥2.5G) up ∼2 kG high-purity single-crystal platelet, field both parallel c axis. The provide more definitive evidence possibly three (at ∼16.8K, 16.0 ∼14.3K, our measurements). These data some support Kuhlow’s conjecture initial phase transition consisting 3D-disordered, 2D-ordered, planes spins. strongest this picture. To clarify situation further neutron scattering (NS) were batch same material. NS temperature-dependence appear additional by showing change curvature magnetization (M) curve near 14K, then apparent linear decrease M above 14K. Additionally, show possible hysteresis 16K during cooling. Possibly (though unlikely) critical-region phase-transition behaviors observed unique system.