Study of the magnetic properties of YbMn2Sb2 single crystals by μSR

•Single crystal growth of CaAl2Si2-type intermetallics.•Spin–lattice coupling observed from magnetization and structural properties.•Muon spin study in a classical Heisenberg system revealing a strongly disordered magnetic ground state. The crystal growth and the structural, transport and magnetic properties of YbMn2Sb2 single crystals are reported. The crystals show a trigonal symmetry of La2O2S-type structure (space group P3¯m1, N. 164, hP5), 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 specific heat measurements confirm successive features at 40 K, 116 K and 225 K, being the phase 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 a static and strongly disordered magnetic ground state. The role of spin–lattice coupling and its relationship with exchange interactions between Mn moments is discussed as a possible cause of the magnetic behavior observed.