Manganese

Doublet Separations

Mn 2p: 11.2 eV (metal)
Mn 2p: 11.7 eV (oxides)
Mn 3s: Variable – see experimental section below

Available Photoemissions and Energies

The Energies Listed are Binding Energies!

Mn 2s: 769 eV
Mn 2p: 641 eV
Mn 3s: 84 eV
Mn 3p: 49 eV
Mn 3d: 4 eV

MnO2 Survey — Survey scan of MnO2 by XPS, showing relevant peak positions for Mn emissions

Common Element Overlaps

The Energies Listed are Binding Energies!

Sb is primarily analyzed via the 3d orbital

Ra 4d (636 eV)
Ac 4d (639 eV)
Ni LMM (Al source) (~ 642 eV)
Au 4p (644 eV)
Pb 4p (645 eV)
Cd 3p (651 eV)
Os 4p (655 eV)
In 3p (664 eV)

Mn 2p XPS for MnO2 – showing potential peak overlaps from other elements

Augers and Energies

Energies listed are Kinetic Energies!

Mn MNN: ~ 580 eV

Common Species Binding Energies

The Energies Listed are Binding Energies!

Species	Binding energy / eV	Charge Ref	Ref
Mn(0)	638.6	Au 4f (83.95 eV)	1
Mn(II)	639.3	Au 4f (83.96 eV)	2
Mn(III)	640.8	Au 4f (83.96 eV)	2
Mn(IV)	642	Au 4f (83.96 eV)	2

Common Manganese Binding Energies

It should be noted, that binding energies alone are not of great use when trying to understand Mn XPS – see the sections below for more information

Background and Theory

Manganese speciation using the 2p region can be quite difficult due to complex multiplet splitting, and subtle differences in the binding energy of the various emissions.

Experimental Advice

Often recording the Mn 2p region alone may not be the most practical approach, given the complexities of multiplet splitting in Manganese.

Recording both the Mn 2p, and the Mn 3p provides opportunity for two models in order to confirm the speciation (using the models of Ilton)[2], and if possible, the Mn 3s also. It may not always be possible, given the lower cross-sections of the 3p and 3s orbitals compared to the 2p, and if the sample is low in Mn content these regions may not provide enough signal intensity for accurate modelling.

Fitting Advice

It is common practice to record the Mn 3s peak in order to speciate based on the splitting energy – however Ilton et al report that this is not always reliable when considering mixed oxide systems.[2]

Modelling the Mn 2p is a possibility, and through the systems implemented by Ilton and Biesinger,[1] peak models may be developed that can describe the distinct states within select Mn compounds. Modelling the 3p region using the parameters provided int he work of Ilton, or using standard datasets, provides a second check for the sample which may be advantageous given the complex peak fits involved.

Care should be taken in the interpretation of these datasets, given the vast difference in kinetic energies of the Mn 2p and 3p photoelectrons – and if the samples is inhomogeneous in the z-dimension then this process will not be comparable.

Biesinger, Mark C., et al. “Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and Ni.” Applied Surface Science 257.7 (2011): 2717-2730. Read it online here.
Ilton, Eugene S., et al. “XPS determination of Mn oxidation states in Mn (hydr) oxides.” Applied Surface Science 366 (2016): 475-485. Read it online here.