---
tags: Sb, XPS, Mg, Antimony, Magnesium
---

Mg insertion into Sb layers
===========================

## Sb depostion in literature


### XPS

The 3d XP spectra of Sb is undergoing plasmon loss features that were already described in literature [pollak1974]:

## My results

* To deposit Sb on the Au Crystall of the UHV holder, I found out that the deposition is only working if the Au surface is prior to the experiment roughend.
* Discussion with Mr. B: suprising result, since it looks as if the deposition is diffusion limited. Hypothises of faster diffusion o a surface then in the bulk, that was also reported some time ago by Hubbard et al.
* My results are not in agrrement with the bulk Sb depostion of Da an Zan (on a single crystall).

**Typical CV (19.07.2019):**


### XPS analysis of the deposited Sb layers

* Sb depostion for $t=90$ min to get a Sb layer with a neglegible Au signal in spectra.
* a series of spectra is recordes after sputtering

**Survey spectra:**


* 50 eV resolution
* spectra only shows the Au, Sb, C and O contribution
* After 90 min sputtering in total, the AU surface becomes clearly visble.

**high resolution Sb/O region (15 eV CAE):**


* deconvolution of the spectra is chellenging due to:
* X-ray satelittes of the non monochomatic Mg source ($\alpha_3$, displacement 8.4 eV I=8% and $\alpha_4$ , displacement 10.1 eV I=4.1%)
* humb after the peaks -> plasmon loss see [pollak1974]
* the following was considerered for the deconvolution of the Sb/O region:
* 3d intensity ratios of the Sb peaks (3:2)
* Area of O to fulfill chemcial structure of Sb2O3
* Same G : L ratio for all peaks
* Same FWHM for same chemical nature
* Duiring sputtering the Sb(0) amount is increasing and the Sb(+III) ratio decreasing.
* After 90 min sputtering there is still some Sb(+III) left
* This could also be an artfact out of diffrent sputtering rates for the diffent materials
* Sb(+III) is likley to be formed duiring air contact. Da Xings old measurements show, that the m.p.e. value of Sb formation.
* general idea: QMB experiment in which the m.p.e. value for the dissolution is measured after a certain time of air contact of the deposited Sb film.

**Atomic percenteges:**

| sputter time / min | Sb(0) | Sb(III) |
| -------- | -------- | -------- |
| 0 | 37.32 | 62.68 |
| 15 | 49.47 | 50.26 |
| 60 | 53.88 | 46.12 |
| 90 | 74.65 | 25.35 |

**Maybe the spectra need a new analysis due to the peak postion of the O1s signal. My evalutation: 530 eV, Literature: 531.5 eV**

### Measuring the amount of formed Sb(+III) in Potential step experiments

**General idea:** Sb(+III) will not contibute to the charge duiring the Sb desolution. The ratio between deposition and desolution charge is investigated after different electrode treatments:


**Results of the desolution process (normalized to the deposition charge):**


**Results in a table:**


### XPS analysis of the Mg deposition into Sb layers

#### CV in glovebox

- Potential jump after two cycles


#### XP Spectra


# Open questions

* diffrence between single crystall bulk deposition and my deposition. Why do I need a rough surface?
* Where is the Sb(+III) coming from? Can we show in an QMB measurement, that it is formed duiring air contact?
* Another way to show, that Sb(+III) is formed after Air contact colud be, just to measure the depostion/desolution current after air contact.
* O1s peak position in the deconvolution

### Literature

[pollak1974] Journal of ELectron Spectroscopy and Related Phenomena, 3 (1974) 381-398!