Coexistence of magnetic states and metamagnetism in the Bi_2-x Cr_xSe₃topological insulators

¹ St. Petersburg State University - St. Petersburg, 198504, Russia
² National Cheng Kung University - Tainan, 70101, Taiwan
³ M.N. Mikheev Institute of Metal Physics, Ural Branch, Russian Academy of Sciences Yekaterinburg, 620108, Russia
⁴ Ural Federal University - Yekaterinburg, 620002, Russia

^(a) maizr@yandex.ru (corresponding author)

Received: 31 December 2020
Accepted: 6 April 2021

Abstract

The dichalcogenide Bi₂Te₃ and Bi₂Se₃ crystals belong to the 3D topological insulator family. Doping the crystals with magnetic ions can break the time-reversal symmetry and open an energy gap at surface Dirac points. This provides the opportunity of manipulating the surface transport and observing the anomalous quantum Hall effect. We studied magnetic properties of three single-crystalline BiCr_xSe₃ samples with , 0.03, and 0.06 within a temperature range from 2 to 300 K. The dc magnetization revealed the coexistence of antiferromagnetic and ferromagnetic ordering and paramagnetism. Their significance depends on the chromium content. The ferromagnetic phase transition was suppressed by high enough magnetic field. The antiferromagnetic transition near 80 K did not shift visibly up to 50 kOe. The Curie-Weiss law approximation gave the effective magnetic moment close to , which corresponds to divalent chromium ions. Metamagnetic phenomena were found for crystals with and 0.06.