Scanning MWCNT-Nanopipette and Probe Microscopy: Li Patterning and Transport Studies.

A carbon-nanotube-enabling scanning probe technique/nanotechnology for manipulating and measuring lithium at the nano/mesoscale is introduced. Scanning Li-nanopipette and probe microscopy (SLi-NPM) is based on a conductive atomic force microscope (AFM) cantilever with an open-ended multi-walled carbon nanotube (MWCNT) affixed to its apex. SLi-NPM operation is demonstrated with a model system consisting of a Li thin film on a Si(111) substrate.

Polymorphism in self-assembled structures of 9-anthracene carboxylic acid on Ag(111).

Surface self-assembly process of 9-anthracene carboxylic acid (AnCA) on Ag(111) was investigated using STM. Depending on the molecular surface density, four spontaneously formed and one annealed AnCA ordered phases were observed, namely a straight belt phase, a zigzag double-belt phase, two simpler dimer phases, and a kagome phase. The two high-density belt phases possess large unit cells on the scale length of 10 nm, which are seldom observed in molecular self-assembled structures.

Potential steps at C₆₀-TiOPc-Ag(111) interfaces: ultrahigh-vacuum-noncontact scanning probe metrology.

Nanoscale structure-electric potential relations in films of the organic molecular semiconductors C(60) and titanyl phthalocyanine (TiOPc) on Ag(111) have been measured under UHV conditions. Noncontact force methods were utilized to image domain structures and boundaries with molecular resolution, while simultaneously quantifying the local surface electric potential. Sensitivity and spatial resolution for the local potential measurement were first established on Ag(111) through direct observation of the electrical dipole and potential step, φ(step) = 10 ± 3 mV, of monatomic crystallographic steps.

TiOPc molecular dislocation networks as nanotemplates for C60 cluster arrays.

By controlled deposition, TiOPc, a molecular semiconductor with anisotropic interactions can generate a molecular film with a characteristic pattern repeat size of 15 nm. This structure then served as a nanotemplate for a superlattice of C(60) clusters with characteristic diameters of 7 nm. As a result, C(60) deposition on the TiOPc film template forms a pattern of nanophase-separated C(60) and TiOPc domains with a characteristic domain size of 7 nm.

Coverage dependent supramolecular structures: C60:ACA monolayers on Ag(111).

The dependence of supramolecular structure on fractional molecular coverage has been investigated for acridine-9-carboxylic acid (ACA) and the C(60):ACA binary molecular system. The coverage-dependent phase diagram for ACA is first determined from room-temperature STM imaging. At low molecular coverages (theta < 0.

Chiral symmetry breaking in two-dimensional C60-ACA intermixed systems.

We have demonstrated a method for fabricating C60 overlayers with controlled spacing and chirality by reactive coadsorption with the aromatic molecule acridine-9-carboxylic acid (ACA). Structural control is achieved by the mismatched symmetries of the coadsorbates, as well as specific intermolecular and adsorbate-substrate interactions. The resulting supramolecular structure has a C60 period nearly three times as large as the normal C60 2D packing of 1 nm and exists in enantiopure domains with robust chirality.