Single crystal growth of antiferromagnetic Mn3Si by a two-phase RF floating-zone method

The floating-zone growth of massive intermetallic single crystals is very often unsuccessful due to unfavorable solid–liquid interface geometry and insufficient mixing of the melt which depends on the flow in the molten zone. A tailored magnetic two-phase stirrer system with radio frequency (RF) heating has been developed which enables the control of the melt flow by a significant change of the flow field. The magnetic system was used for the crystal growth of the Heusler compound Mn3Si due to their interesting properties such an itinerant antiferromagnetic and incommensurate spin-density wave state. The grown crystals were oriented and cut to samples with the crystallographic orientations (100) and (110) normal to a plane. Measurements of the temperature dependence of magnetization and specific heat are discussed in terms of contributions of other thermodynamic phases and phase transitions. ► Single crystals of Heusler Mn3Si were grown using magnetic field controlled RF-floating-zone. ► Magnetic phase transition at about 23K was confirmed by specific heat measurements. ► Permanent magnetic moments are detected even above the ordering temperature of the majority phase. ► A probable small residual amount of impurity phase (Mn5Si2) may cause ferromagnetic contribution. ► Otherwise, it can possibly be related to a spin glass magnetic order (not to majority Mn3Si phase).