Soft X-ray Reflectivity Beamline

Beamline overview

Indus 2 BL-3

The soft x-ray energy region available from Indus-2 offers a great opportunity to pursue fundamental studies and carryout new technological developments. In the soft x-ray region x-ray reflectivity becomes very powerful tool to probe low contrast system such as carbonaceous soft condensed matter films as it enables one to enhance the contrast among low Z elements near the absorption edges of respective elements. A reflectometry facility has been setup at Indus-2 synchrotron source to pursue various pure and applied research programs

The Beamline
Inside view of monochromator
The Beamline
Inside view of monochromator

Optical layout and beamline parameters

Energy Range100-1500 eV
Flux109 1011 ph/sec
Resolving power1,000-5,000
Beam Size~ 0.1 mm (V) x 0.9 mm(H), @ 1000 eV
MonochromatorVLS-PGM 3 gratings
Beamline parameters & Optical layout
  1. The soft x-ray reflectivity beamline uses a constant deviation angle variable line spacing plane grating monochromator with Hettrick type optics.
  2. The first optical element of the beamline is a horizontally deflecting and vertically mounted toroidal mirror, TM1, which accepts 2 mrad (H) and 3 mrad (V) of the emitted bending magnet radiation.
  3. TM1 focuses the light vertically on to the entrance slit S1, and horizontally on to the exit slit S2.
  4. The second mirror is a spherical mirror SM, which is vertically deflecting and forms a convergent beam on the plane grating.
  5. Three interchangeable gratings G1, G2 and G3 of line densities 1200, 400 and 150 lines/mm are used to efficiently cover the whole energy region of 100 - 1500 eV.

Experimental Techniques

The experimental station consists of a two -axes high -vacuum compatible goniometer with x-y-z sample manipulation stages. The scattering geometry is in the vertical plane which is suitable for s-polarized reflectivity measurements as synchrotron light is plane polarized in the horizontal plane.

Experimental station
Sample Stage

The existing sample holder can accommodate a sample of size up to 300 mm length, 100 mm width and 50 mm height. The maximum weight of the sample in existing configuration can be about 5 Kg. Detector distance from the axis of rotation is 300 mm.

Experimental facility

1. Soft x-ray reflectivity:
Soft x-ray reflectivity
2. Soft x-ray Absorption:
Soft x-ray Absorption:
3. Soft x-ray Fluorescence:
Soft x-ray Fluorescence
Representative Soft x-ray fuorescence spectra of Cu, Al, GaAs
Soft x-ray Fluorescence

Application Areas

The experimental station of the beamline is a versatile instrument to measure the x-ray reflectivity, x-ray absorption and x-ray fluorescence signals in the soft x-ray region. These techniques provide information about the materials composition, electronic properties and structural information about the thinfilm/ multilayer samples, surface/interface roughnesses, density profiles etc. These techniques have broad application areas in materials science, condensed matter chemistry, x-ray instrumentations, etc.

X-ray Optics

Reflectivity performance of reflective optics of ~300 mm length can be performed.


Detector active area of 50 mm x 50 mm can be scanned. Overall size of the detector should be within ~300 mm length, ~150 mm width and ~50 mm height.

Surfaces and interfaces characterizations

Angle dependent reflectivity technique is applied to analyse the depth profiles of a thinfilm and multilayer structures.

Chemical and electronic properties

Soft x-ray fluorescence, Soft x-ray absorption and near edge Soft x-ray reflectivity techniques together are used for chemical and electronic structure analyses of thinfilms and other suitable samples

1. Effect of electronic transitions on near edge optical properties of off-stoichiometric boron carbide thin films
Mohammed H. Modi, Rajkumar Gupta, Praveen Kumar Yadav, Shruti Gupta, C. Mukherjee, Mourad Idir
J. Appl. Phys. 133, 165302 (2023)
2. Assessment of bonding character of β-(AlxGa1-x)2O3 alloys from photoluminescence and x-ray absorption near edge spectroscopy,
Jayanta Bhattacharjee, R. K. Gupta, and S. D. Singh
Appl. Phys. Lett., 122, 152104 (2023)
3. Study of oxidation behaviour of Ruthenium thin film after thermal annealing in oxygen environment
Shruti Gupta, Mangalika Sinha, R .Dhawan, R. Jangir, A.Bose, P.Gupta, M.K. Swami, Mohammed H. Modi
Thin Solid Films 764, 139606 (2023).
4. Boron carbide (BxC) thin film surface characterization after graphitic carbon removal using low pressure oxygen gas RF plasma
Praveen K Yadav, Raj Kumar Gupta, Shruti Gupta, C Mukherjee, UK Goutam, Mohammed H Modi
Appl. Opt., 62, 1399 (2023).
5. Boron migration during amorphous to crystalline transformation in CoFeB/MgO multilayers: A reflectivity study
Pramod Vishwakarma, Gagan Sharma, M.H. Modi, Mukul Gupta, D.M. Phase, Jochen Stahn, Ajay Gupta
Materials Research Bulletin 161, 112150 (2023).

1. Study of interface reaction in a B4C/Cr mirror at elevated temperature using soft X-ray reflectivity
Mohammed H. Modi, Shruti Gupta, Praveen K. Yadav, Rajkumar Gupta, Aniruddha Bose, Chandrachur Mukherjee, Philippe Jonnard and Mourad Idir
J. Synchrotron Rad. 29 (2022).
2. Electronic structure modification in Fe-substituted β-Ga2O3 from resonant photoemission and soft x-ray absorption spectroscopies
Sahadeb Ghosh, Mangla Nand, Rajiv Kamparath, Mukul Gupta, Devdatta M Phase, SN Jha, Shreyashkar Dev Singh, Tapas Ganguli
J. Phys. D: Appl. Phys. 55, 185304 (2022).
3. Interface analysis of Mg/Sc and Sc/Mg bilayers using X-ray reflectivity
Hina Verma, Karine Le Guen, Shruti Gupta, Rajnish Dhawan, Mohammed H. Modi, Philippe Jonnard
Thin Solid Films 763, 139595 (2022).
4. Design of a soft x-ray emission spectrometer setup for soft x-ray reflectivity beamline of Indus-2
Mohammed H. Modi, Praveen K. Yadav, Rajkumar Gupta, Shruti Gupta,
J. Phys.: Conf. Ser. 2380, 012049( 2022 ).
5. Study of ruthenium film grown in oxygen environment for x-ray optics application
Shruti Gupta, R. Dhawan and Mohammed H. Modi, DOI 10.1088/1742-6596/2380/1/012078
J. Phys.: Conf. Ser. 2380, 012078( 2022 ).

1. Effect of surface oxidation on soft x-ray optical properties of ion beam sputter deposited amorphous AlN thin film
Kiranjot, Mohammed Hussein Modi
J. Appl. Phys. 130, 195302 (2021).
2. Investigation of soft X-ray optical properties and their correlation with structural characteristics of zirconium oxide thin films.
Mangalika Sinha, Amol Singh, Raj kumar Gupta, A.K. Yada, Mohammed H. Modi
Thin Solid Films 721, 138552 (2021).
3. Carbon removal from a mirror-like gold surface by UV light, RF plasma, and IR laser exposure: a comparative study
P. K. Yadav, R. K. Gupta, A. K. Choubey, S. Ali, U. K. Goutam, and M. H. Modi
Applied Optics 60, 89-97 (2021).
4. Interface modification of Cr/Ti multilayers with C barrier layer for enhanced reflectivity in the water window regime
P. Sarkar, A. Biswas, N. Abharana, S. Rai, M. H. Modi and D. Bhattacharyya
J. Synchrotron Rad. 28, 224–230 (2021).
5. Ground calibration of Solar X-ray Monitor on board the Chandrayaan-2 orbiter
NPS Mithun, SV Vadawale, M Shanmugam, AR Patel, MK Tiwari, M.H. Modi et al
Experimental Astronomy 51, 33-60 (2021).
6. Evolution of the interface microstructure of short-period Cr/Ti multilayers with increase in number of bi-layers
P Sarkar, A Biswas, S Rai, MH Modi, Gurupada Ghorai, Pratap K Sahoo, D Bhattacharyya
Thin Solid Films 734, 138840 (2021).

1. Influence of spin orbit splitting and satellite transitions on nickel soft X-ray optical properties near its L2,3 absorption edge region
Kiranjot, M. H. Modi, R. K. Gupta, M. Sinha and P. K. Yadav
J. Synchrotron Rad. (2020). 27, 1633-1639
2. Solar X-Ray Monitor on Board the Chandrayaan-2 Orbiter: In-Flight Performance and Science Prospects
N.P.S. Mithun, Santosh V. Vadawale, Aveek Sarkar, M. Shanmugam, Arpit R. Patel, Biswajit Mondal, Bhuwan Joshi, P. Janardhan,Hiteshkumar L. Adalja, Shiv Kumar Goyal, Tinkal Ladiya, Neeraj Kumar Tiwari1, Nishant Singh, Sushil Kumar, Manoj K. Tiwari3,M.H. Modi, Anil Bhardwaj
Solar Physics 295, 139 (2020)
3. Effect of zirconium oxide local structure on soft X-ray optical properties near the oxygen K-edge region
M. Sinha, R.K. Gupta,  Kiranjot, Amol Singh, Mohammed H Modi
J. Appl. Phys 128, 065302 (2020)
4. Interface asymmetry in AlN/Ni and Ni/AlN interfaces: a study using resonant soft x-ray reflectivity
Kiranjot, R. Dhawan, R.K. Gupta, P. Yadav, Mohammed H Modi
Applied Surface Science, 529, 147199 (2020)
5. Interface evolution of Cr/Ti multilayer films during continuous to discontinuous transition of Cr layer"
P.Sarkar, A. Biswas, S. Rai, H. Srivastava, S. Mandal, M.H. Modi and D. Bhattacharyya
Vacuum 181, 109610 (2020)
6. "Interface evolution of Co/Ti multilayers with ultra-short period"
P.Sarkar, A. Biswas, S. Ghosh, S. Rai, M.H. Modi and D. Bhattacharyya
Thin Solid Films 693, 137688 (2020)
7. Interfacial Chemistry and Electronic Structure of Epitaxial Lattice-matched TiN/Al0.72Sc0.28N Metal/Semiconductor Superlattices Determined with Soft X-Ray Scattering
Bidesh Biswas, Sanjay Nayak, Vijay Bhatia, Ashalatha Indiradevi Kamalasanan Pilla, Magnus Garbrecht, M. H. Modi, Mukul Gupta and Bivas Saha
J. Vac. Sci. Tech. A 38, 053201 (2020)
8. Analysis of Au film surface after carbon layer removal with ultra violet radiation, RF plasma and IR laser
P. K. Yadav, R. K. Gupta, A. K. Choubey, Sabir Ali, and M. H. Modi
AIP Conference Proceedings 2265, 030253 (2020);
9. Soft X-ray photon energy calibration using multilayer mirror
Kiranjot, Mangalika Sinha, R. K. Gupta, P. K. Yadav, and Mohammed H. Modi
AIP Conference Proceedings 2265, 030196 (2020);

1. Continuous optical constants (δ & β) spectra of aluminium oxide near Al L and O K-edge region
M. Sinha, R.K. Gupta, P. Dasilva, P. Mercere, M.H. Modi
AIP Conference Proceedings 2115 (1), 030207 (2019)
2. A soft x-ray reflectivity beamline for 100-1500 eV energy range at Indus-2 synchrotron radiation source,
M.H. Modi, R.K. Gupta, S.R. Kane, V. Prasad, C. Kant, P.K. Yadav, V.K. Raghuwanshi., Singh Amol, Sinha M.
AIP Conf. Proc, 2054, 060022,Jan.2019.
3. Glancing angle soft x-ray reflectivity (SXR) and total electron yield (TEY) characterization of ZrO2 thin film near O K edge,
Mangalika Sinha, Amol Singh, R.K. Gupta R.K., M.H. Modi
AIP Conf. Proc, 2054, 040004,Jan.2019.
4. Interface Studies of Mo/Si Multilayers with Carbon Diffusion Barrier by Grazing Incidence EXAFS
N. Abharana, A. Biswas, P. Sarkar, P. Rajput, Rajnarayan De, K.D. Rao, M.H. Modi, D. Bhattacharyya, S.N. Jha and N.K. Sahoo
Thin solid films 673, 126-135 (2019)

1. Studies on thin films & multilayers using soft x-ray reflectivity beamlines at Indus synchrotron sources
M.H. Modi, R.K. Gupta, P.K. Yadav
Physics News, bulletin of the Indian physics association, Vol. 48, p. 70, 2018
2. Thermal and temporal stability of W∕B4C multilayer mirrors for space-based astronomical applications
Panini S. Singam, Maheswer Nayak, Rajkumar Gupta, Paresh C. Pradhan, Arindam Majhi, Shyama Narendranath, and Parameswaran Sreekumar
J. Astron. Telesc. Instrum. Syst. 4(4), 044003 (2018), doi: 10.1117/1.JATIS.4.4.044003
3. Optical performance of W/B C multilayer mirror in 4 the soft x-ray region
P. C. Pradhan, A. Majhi and M. Nayak,
J. Appl. Phys., 123, 095302 (2018)
4. Soft x-ray characterization of ion beam sputtered Magnesium oxide (MgO) thin film
Mangalika Sinha, Mukul Gupta, Philippe Jonnard, Mohammed H. Modi
Surf. Interface Anal.; 2018 DOI: 10.1002/sia. 6446

Science Highlights

Science Highlights
Effect of electronic transitions on near edge optical properties of off-stoichiometric boron carbide thin films

J. Appl. Phys. 133, 165302 (2023).

Science Highlights
Assessment of bonding character of β-(AlxGa1-x)2O3 alloys from photoluminescence and x-ray absorption near edge spectroscopy

Appl. Phys. Lett. 122, 152104 (2023).

Science Highlights
Boron migration during amorphous to crystalline transformation in CoFeB/MgO multilayers: A reflectivity study

Materials Research Bulletin 161, 112150, (2023)

Science Highlights
Interface analysis of Mg/Sc and Sc/Mg bilayers using X-ray reflectivity

Thin Solid Films 763, 139595 (2022).

Science Highlights
J. Synchrotron Rad. 29 (2022)

Science Highlights
J. Phys. D: Appl. Phys. 55, 185304 (2022)

Science Highlights
Thin Solid Films 721 (2021) 138552

Science Highlights
J. Synchrotron Rad. 28 (2021) 224–230

Science Highlights
Applied Optics 60 (2021) 89

Team members

Dr. Mohammed H. Modi 0731-244 2121
Dr. Praveen Kumar Yadav 0731-244 2107
Shri Rajkumar Gupta 0731-244 2107
Ms Shruti Gupta 2587
Shri Pushkardeep 0731-244 2503

Beamline Phone Number: 0731- 244 2503

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