Interactive Tool Nanoparticle Size Analysis

Lognormal Distribution Analyzer

Nanoparticle synthesis routinely yields skewed particle size distributions best described by lognormal statistics. Use this live tool to simulate or analyze distributions, calculate geometric mean ($\mu_g$) and geometric standard deviation ($\sigma_g$), and inspect the histogram.

Median: 5.00 nm
Arithmetic Mean: 5.13 nm
Polydispersity Index: 0.05
Sampled Histogram Fitted Lognormal PDF
Interactive Calculator

Chi Pauli & Density of States Calculator

Used for Evans method measurements: computes chi_Pauli (Pauli paramagnetic susceptibility) and electronic density of states at the Fermi level from NMR shift measurements.

Designed for processing Evans method NMR experiments on colloidal metallic nanoparticles.

Input the measured chemical shift difference ($\Delta \nu$), solvent magnetic susceptibility, nanoparticle mass concentration, and core density to directly derive:

  • $\chi_{\text{Pauli}}$ (Pauli susceptibility)
  • $D(E_F)$ (Electronic density of states at the Fermi level)
  • Effective magnetic moment per particle
NMRElectronic StructureSusceptibility
Interactive Web App

Lognormal Fitter

Takes measured nanoparticle size distributions and computes histograms with single or multi-component lognormal distribution fits, exporting fitted parameters and publication-ready CSVs.

Nanoparticle synthesis routinely yields size distributions governed by lognormal statistics. This tool streamlines the analysis process:

  • Paste or upload columns of diameter measurements (TEM, AFM, DLS).
  • Automatically generate customizable histograms with adjustable bin counts.
  • Perform non-linear least squares fitting to single or multi-modal lognormal distributions.
  • Export high-resolution SVG/PNG plots and CSV summary tables of geometric mean and standard deviation.
NanoparticlesData AnalysisJavaScript
Python Library / Scripts

Spectroscopy Workup Scripts

Custom Python scripts for fitting EPR spectra and calculating Evans method shifts from NMR data.

NMR Shift Evaluator: Accepts two CSV files with NMR spectra and computes Evan shift and paramagnetic susceptibility. Uses lmfit, scipy, and matplotlib.

EPR Fitter: Fits EPR spectra to isotropic and rhombic patterns with Gaussian, Lorentzian, Pseudo-Voigt, or CESR line shapes.

Python EPR NMR lmfit

Curated Physical & Materials Resources

Recommended external literature and essential reference texts for group members and colleagues:

  • Magnetism in Condensed Matter • Stephen Blundell (Oxford Master Series in Physics)
  • Introduction to Solid State Physics • Charles Kittel
  • Electron Paramagnetic Resonance of Transition Ions • Abragam and Bleaney / John R. Pilbrow
  • Spin Resonance Spectroscopy: Principles and Applications • Kaupp, Köhler, Nanda