Magnetostrictive self-assembly UnivCollegeLondon ScanningSpreadingResistanceMicroscopy hard_disk_media DLaTGS nanomechanical H-BN Piezo ForceVolumeMapping semifluorinated_alkanes temp_control NanoLithography StainlessSteel Mfm PMNPT FM_SKPM Deposition hetero_structure ScanningKelvinProbeMicroscopy NiFe Granada Polyvinylidene_fluoride Ceramics YszSubstrate Optoelectonics DataStorage dielectric trench StrontiuTitanate CrossSection Patterns ferromagnetic Potential Lift Change