Related Experiment Video
Updated: Aug 7, 2025

Analysis of Complex Molecules and Their Reactions on Surfaces by Means of Cluster-Induced Desorption/Ionization Mass Spectrometry
Published on: March 1, 2020
Inverse Volcano: A New Molecule-Surface Interaction Phenomenon
Michelle S Akerman1, Roey Sagi1, Micha Asscher1
1Institute of Chemistry, Edmund J. Safra Campus, Givat-Ram The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Abstract:
Explosive desorption of guest molecules embedded in amorphous solid water upon its crystallization is known as the "molecular volcano." Here, we describe an abrupt ejection of NH_{3} guest molecules from various molecular host films toward a Ru(0001) substrate upon heating, utilizing both temperature programmed contact potential difference and temperature programmed desorption measurements. NH_{3} molecules abruptly migrate toward the substrate due to either crystallization or desorption of the host molecules, following an "inverse volcano" process considered a highly probable phenomenon for dipolar guest molecules that strongly interact with the substrate.
More Related Videos
Related Concept Videos
Van der Waals Interactions
Phase Transitions: Vaporization and Condensation
Volatilization
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation
Van der Waals Equation
First, the attractive forces between molecules, which are stronger at higher densities and reduce the pressure, are considered by adding to the pressure a term equal to the square of the molar density multiplied by a positive coefficient a. Second, the volume...

