Field-induced anisotropic magnetic phase transitions and tricritical phenomena in GdCr6Ge6

• Published in: Science China. Physics, mechanics & astronomy Vol. 66; no. 9; p. 297511
• Main Authors: Du, Zan, Rahman, Azizur, Song, Jiangpeng, Zhao, Jun, Liu, Wei, Fan, Jiyu, Ma, Chunlan, Ge, Min, Xiong, Yimin, Pi, Li, Zhang, Lei, Zhang, Yuheng
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.09.2023; Springer Nature B.V
• Subjects: Anisotropy; Astronomy; Classical and Continuum Physics; Exponents; Ferromagnetism; Gadolinium; Magnetic anisotropy; Magnetic properties; Magnetization; Observations and Techniques; Phase diagrams; Phase transitions; Physics; Physics and Astronomy; Rare earth elements; Single crystals; Temperature dependence; RT; anisotropic interaction; X; critical analysis; compounds; tricritical phenomenon; field-induced phase transition
• ISSN: 1674-7348; 1869-1927
• DOI: 10.1007/s11433-023-2155-6

The interaction between complex magnetic structures and non-trivial band structures in ternary rare-earth GdCr 6 Ge 6 induces exotic and abundant electro-magnetic phenomena. In this work, we perform a systematical investigation on critical behaviors and magnetic properties of the single-crystal GdCr 6 Ge 6 . The temperature, field, and angle dependence of magnetization unveils strong magnetic anisotropy along the c -axis and isotropic characteristic in the ab -plane. Critical exponents β = 0.252(1), γ = 0.905(9), δ = 4.606(3) for H//ab, and β = 0.281(3), γ = 0.991(8), δ = 4.541(5) for H//c are obtained by the modified Arrott plot method (MAP) and critical isotherm (CI) analysis. The determined exponents for both directions are consistent with the theoretical prediction of a tricritical mean-field model. Based on detailed magnetization measurements and universality scaling, comprehensive magnetic phase diagrams of GdCr 6 Ge 6 for H//ab and H//c are constructed, which reveal that the external field induces a ferromagnetic (FM) transition for H//ab while a ferrimagnetic (FIM) one for H//c . Two tricritical points are determined for H//ab (11.2 K, 266.3 Oe) and H//c (11.3 K, 3.3 kOe) on the phase diagrams, respectively. The field-induced anisotropic magnetic configurations and multiple phases are clarified, where the moments of Gd and Cr form FM coupling for H//ab while FIM one for H//c via the interaction between Gd and Cr sublattices.