Chemical and physical pressure-tuned magneto-structural coupling in MnCoGe alloys

MnCoGe alloys show a variety of intriguing phenomena like magneto-caloric effect, baro-caloric effect and negative thermal expansion. Our recent results show that chemical and physical pressures play similar roles in coupling/decoupling the magnetic and structural transitions in the MnCoGe alloys. Both of them vary the interatomic distances, which strongly influences the magnetic interactions and chemical bonds. Nevertheless, unlike its chemical couterpart, the physical pressure does not suffer from parasitic effets originating in the substitution itself, since it retains the composition, purity and the number of valence electrons in the sample. Consequently, a comprehensive study on the evolution of the magnetic and crystallographic structures under chemical and physical pressures can provide essential insight into the origin of the magneto-structural transition in the MnCoGe alloys.