Магистрский проект по Физике

MINISTRY OF EDUCATION AND SCIENCE REPUBLIC OF KAZAKHSTAN

K.. ZHUBANOV AKTOBE REGIONAL STATE UNIVERSITY

MASTER ’ S PROJECT

Methods of studying the complex of programs for processing experimental spectra

MASTER ’ S PROJECT

Fulfilled master of specialty

Academic adviser, c. ph.-m. s.,

6М011000-Physics Bersiyeva M. Y.

docent of the chair

Zhubaev A. K.

MASTER ’ S PROJECT

The relevance of the topic of the master's project. Mossbauer spectroscopy is one of the most effective methods for the study of locally inhomogeneous systems (LIS). The local nature of the information received, combined with information on cooperative phenomena, allows for research that is not available to other methods. Mossbauer spectroscopy can provide a wealth of information about the features of the macro - and microscopic state of matter, including those that do not have a regular structure. Currently, the study of LIS has become, in fact, a new independent direction in Mossbauer spectroscopy

The aim of the master's project: to uncover the functional capabilities of the software complex an MSTools.

To achieve this aim, it is necessary to solve the following problems:

1) Describe ways of extracting information from Mossbauer spectra; reveal methodological aspects of processing and analysis of Mossbauer data;

2) to conduct the processing of the experimental Mossbauer spectra;

3) Perform modeling of Mossbauer spectra on the phase nuclei presented in the phase diagram of the Fe–Sn binary system.

MASTER ’ S PROJECT

Scientific novelty of the master's project. In the first phase modeled Mossbauer spectra present at the phase diagram of a binary Fe-Sn system.

Practical significance. The results obtained in the master's thesis are used for the analysis and processing of experimental data, as well as the developed technique can be used to teach the subject " Nuclear physics".

Approbation of the project. On materials of thesis published 1 article in the "Bulletin of the ARSU" (2018, №1), presented the report 2 of the International Scientific and Practical Internet Conference (27-30 March 2018, Mozyr, Belarus), prepared a report on 1 International Congress EFRE -2018 (16-22 September 2018, Tomsk) and 1 article in the Journal of Physics: Conference Series (JPCS, IOP Publishing).

MASTER ’ S PROJECT

The Mossbauer effect, or recoilless nuclear resonance fluorescence, is a physical phenomenon discovered by Rudolf Mossbauer in 1958. It involves the resonant and recoil-free emission and absorption of gamma radiation by atomic nuclei bound in a solid. Its main application is in Mossbauer spectroscopy.

In the Mossbauer effect, a narrow resonance for nuclear gamma emission and absorption results from the momentum of recoil being delivered to a surrounding crystal lattice rather than to the emitting or absorbing nucleus alone. When this occurs, no gamma energy is lost to the kinetic energy of recoiling nuclei at either the emitting or absorbing end of a gamma transition: emission and absorption occur at the same energy, resulting in strong, resonant absorption.

For data processing and analysis the Mossbauer spectra of the used software complex youhave an MStools.

Transcript of the experimental spectra is carried out by performing the following tasks: search and identification of the resonance lines in the spectrum, the choice of the optimal model of transcription for all samples of this series, decoding and interpretation of the original spectra in the framework of the accepted model [1].

Mossbauer spectroscopy

MASTER ’ S PROJECT

Currently MSTools complex consists of ten programs for processing and analysis of both experimental Mossbauer spectra and their parameters (see. Figure 1) [4]. The complex provides:

• resolution enhancement and efficient noise reduction in the spectrum (the calculation hardware features, operational characteristics, correlation functions, the frequency spectra of the noise filtering function and a false signal values ​​to most known linear method) (RESOL);

Mossbauer spectra model decoding using a priori information on the object of study (SPECTR)

restoration of the distribution functions of the partial spectra parameters - hyperfine magnetic field, shear displacement quadrupole Mossbauer linewidth (DISTRI);

restoration of the distribution functions of the partial spectra parameters - hyperfine magnetic field, shear displacement quadrupole Mossbauer linewidth (DISTRI);

Quantitative phase analysis using reference spectra of samples (PHASAN);

calculation parameters and modeling of the spectrum of any Mossbauer isotope generally combined electric and magnetic hyperfine interactions for poly- and single crystal at a predetermined geometry of the experiment (HAMILTON);

calculation lattice sums and estimates of tensor components of the electric field gradient, quadrupolar line bias dipole contribution to the hyperfine magnetic field in the case of a regular lattice and the cluster formations (LATTICE);

processing temperature and shear area depending Mossbauer lines in the Debye and enshteynovskom approximations vibrational spectrum resonance nucleus (DYNAMICS);

processing temperature and field dependencies hyperfine field within the theory of similarity, spin-wave theory and the effective molecular field model (FIELD);

processing dependencies spectrum parameters using the kinetic equations and search for the parameters of these equations (KINETICS);

Mossbauer analysis results of the temperature scanning (SCAN);

MASTER ’ S PROJECT

Service capabilities MSTools software.

1. To organize a single style of communication - "Window" dialog in which the user is notified as an error committed by them, and of corrective recommendations.

2. Marketed control process and the result of each iteration.

3. To use the graphical and tabular methods of presenting information.

4. There is full compatibility of the complex programs on raw data files.

5. You can create banks of the initial experimental data processing models and accounts results.

6. Has the ability to view and select the directory of the current directory, create, view, edit, and copy files.

7. Given the opportunity to generate data for later image editors.

MASTER ’ S PROJECT

Figure 2 is a diagram illustrating the relationship of various programs MSTools by Mossbauer spectra analysis and processing methods.

MASTER ’ S PROJECT

Mossbauer spectra Characteristic 57 Fe nuclei under study in a layered system Sn (0,5mkm) -Fe (8mkm) -Sn (0,5mkm) after sequential isochronous annealing in the temperature range of 400-700  C shown

MASTER ’ S PROJECT

The Mossbauer spectrum obtained after annealing the Sn-Fe-Sn sample at 700°C and the corresponding distribution function of the hyperfine magnetic field p (H n )

MASTER ’ S PROJECT

This project presents the results of modeling the phase spectra presented on the phase diagram of the binary Fe-Sn system.

The phase diagram of the binary system Fe-Sn is taken as an object of investigation. A complex of methods for processing and analyzing Mössbauer data, implemented as a software package of MSTools [14], was used in our project. Currently, the MSTools complex consists of ten programs designed to process and analyze both the experimental Mossbauer spectra and their parameters. To achieve the purpose of the work, a model decoding of the Mossbauer spectra using a priori information about the object of research (SPECTR) was used.

MASTER ’ S PROJECT

Parameters Mossbauer spectra on nuclei 57 Fe phases Fe-Sn binary system at room temperature

Chemical formula

The isomer shift  (Rel.  -Fe), mm / c

 -Fe

quadrupole shift  Mm / s

~0

Fe3Sn

Hyperfine magnetic field Hn, kgf

0.24 ± 0.04

Fe5Sn3

~0

0.32±0.1

Fe3Sn2

0.15  0.06

The intensity ratio of the partial spectra

330.4

254  5

0.37 ± 0.01

042±0.1

FeSn

FeSn2

0.45±0.1

171  3

0.11 ± 0.02

-0.41±0.02

0.51±0.01

231  3

196  3

-0.45±0.02

120.9  1.5

 0

185  3

113.6  1.5

113  1

1

101.4  1.5

1

1

MASTER ’ S PROJECT

Thus, to solve the binary system modeling tasks necessary to create a model intermetallic compounds

After starting the program the total SPECTR menu consisting of five teams (four of which have a pop-up command), and submenu # Help line (see. Figure 1). Help string accompanies the General menu, submenus and menu items, and provides information on hotkeys and ways to scroll through the menus. All available commands are marked with bright colors. Movement there between is done by arrow keys.

General menu and submenu #

The submenu of experimental data Experimental Data

Optional Components submenu experimental data

Submenu of variable parameters

Upon completion of the input of the modeled spectrum parameters from the following options Control Graph, it is possible to observe the desired spectrum. Symmetrical spectrum situated in the lower parts of the screen represents the difference between the original spectrums (white dots) superimposed on it and the model (pink curve).

Modeled spectrum 57Fe atoms in  -Fe

For further work will use the difference spectrum. In order to select it in the submenu processing

The newly created reference spectrum  -Fe

In the project the results Mossbauer studies on nuclei 57 Fe and 119mSn antiferromagnetic FeSn compound at temperatures from 77K to the magnetic transition temperature.

As the object of research is taken a phase diagram of a binary system Fe-Sn.Mossbauer spectra decoding model, realized as a program SPECTR MSTools software package was used

As described in [39] spectra of Fe-Sn binary system phase were established. Figure 1 shows the spectra obtained tin nuclei in different lattice positions crystalline phases present in the system state diagram.

The reference spectra 119Sn nuclei in the different phases:

(a) – β-Sn, (b) – FeSn 2 , (c-d) – FeSn, (e-f) – Fe 3 Sn 2 , (g) – Fe 3 Sn

The simulated spectra 119Sn nuclei in the different phases:

(a) – β-Sn, (b) – FeSn 2 , (c) – FeSn, (e) – Fe 3 Sn 2 , (f) – Fe 3 Sn

CONCLUSION

Methods of Mossbauer spectroscopy continue to develop rapidly and are widely used in various fields of physics, chemistry, geology, mineralogy, soil science, biology, medicine, materials science and industry. Almost immediately after the discovery of the effect, it became clear that Mossbauer spectroscopy is a powerful nuclear method for studying matter in the condensed state.

Mossbauer spectroscopy is characterized by the diversity and richness of the information obtained, which often cannot be obtained by other methods, as well as the combination of local information with data on cooperative phenomena.

The Mossbauer core is a probe located in a solid body, with which it is possible to study the dynamic properties, structural, valence and charge States of the Mossbauer atom, as well as the phase composition, features of the atomic, crystalline, magnetic and electronic structures of the substance under study.

The software package is designed for effective use in Mossbauer spectroscopy. Of particular interest is the use of other spectroscopic information for processing.

Using the software complex MSTools, we developed a method for processing Mossbauer spectra.

Results of this project:

• Considered software package MSTools, which is designed for processing and analysis of the experimental Mossbauer spectra. Identified problems arising when using methods Mossbauer spectroscopy.
• PREPSPEC considered a program that is designed to prepare the initial experimental spectra for further processing. Considered SPECTR program that implements a model spectrum processing described by a finite number of partial spectra. Detailed description of all of the work with these programs options.
• A method for processing Mossbauer spectra modeling methods decrypt and restore hyperfine parameter distribution function. The method of decoding a model spectra were processed layer system Sn-Fe-Sn. Intensity obtained partial spectra for different phases.
• The studies were modeled spectra 57 Fe and 119 Sn nuclei in different states in the intermetallic compounds and the solid solution in the binary system of Fe-Sn.

The results obtained in the master's thesis are used for the analysis and processing of experimental data, as well as the developed technique can be used to teach the subject " Nuclear physics".