As a part of the short-term interinstitutional mobilities we have organised the training dedicated to the high-resolution transmission electron microscopy imaging and lamellae preparation by conventional techniques and focused-ion beam method. The training was held in Budapest at the Centre for Energy Research MFA and led by Dr Ildikó Cora and attended by the PhD students from the CUBES founding institutions. During this intensive training, multiple advanced gallium oxide samples were prepared and investigated – the achieved results will be disseminated in form of peer-reviewed publications.