Complex magnetic order in YbMn2Sb2 single crystals observed by μSR
Abstract
The crystal growth and the structural, transport and magnetic properties of the magnetically frustrated YbMn2Sb2 single crystals are reported. The crystals show a trigonal symmetry (space group P3m1), where corrugated honeycomb layers of MnSb are separated by Yb atoms. No structural phase transition was observed down to 22~K. The resistivity measurements show a predominantly insulating behavior. The combined resistivity, dc susceptibility and heat capacity measurements confirm successive transitions at 230~K, 116~K and 27~K, being the transition at TN=116~K due to the Mn+2 lattice antiferromagnetic ordering. Muon spin rotation experiments (μSR) reveal a more complicated scenario, with temperature dependence of the magnetic volume fraction reflecting short range and long range magnetic order, and a strongly disordered magnetic ground state. The role of spin-lattice coupling and its relationship with exchange interactions between Mn moments are discussed as possible cause of the complex magnetic behavior observed.