My name is Hossein Khosroabadi. I was born in 1977 in Sabzevar city of Iran, and grow up in Tehran. After finishing my high school I continued my college at Mazandaran University to become graduated in Solid State Physics in Sep 1998. I continue my Master and Doctorate in the filed of High Temperature Superconductivity (HTSC) under the supervision of Prof. M. Akhavan at Sharif University of Technology, and defended them in 2000 and 2006 respectively. My research in that period was concentrated on transport measurements and ab-initio calculation of YBCO family of HTSCs. Now, I continue my interests by investigating the phonon properties of Ba1-xKxBiO3 crystals by Inelastic X-ray Scattering experiments.
My hobbies are hiking, chess, cooking and watching movies.
Some parts of my CV and the abstract of my studies are presented in the following:
Awards and Honors
- Iran Physical Society Award for Excellent Research PhD study in Iran (2006).
- Japanese Society for Promotion of Science postdoctoral fellowship for two years, Osaka Univ., Japan (2006).
- International Junior Associate program, International center for theoretical Physics, Italy (2005).
- Distinguished National Ph.D. Student of Iran (2004).
- Khwarizmi Young Award, 1st place (2002).
- Iran Physical Society Award for Best Achievement in Research (2001).
Publications
1. H. Khosroabadi, B. Mossalla, and M. Akhavan, Phys. Rev. B 76 (2007) 54508 [selected by the Virtual Journal of Applications of Superconductivity, Aug. 15, 2007].
2. H. Khosroabadi, B. Mossalla, and M. Akhavan, Phys. Stat. Sol. 3 (2006) 3140.
3. H. Khosroabadi, A. Tavana, and M. Akhavan, Eu. J. Phys. B 51 (2006) 161.
4. H. Khosroabadi, A. Tavana, B. Mossalla, and M. Akhavan, Iran. J. Phys. Res., Special Issue of Two Decades of HTSC, 6 (2006) 187.
5. A. Tavana, H. Khosroabadi, and M. Akhavan, Phys. Stat. Sol. 3 (2006) 3162.
6. H. Khosroabadi, and M. Akhavan, J. of Superconductivity 18 (2005) 269.
7. H. Khosroabadi, B. Mossalla, and M. Akhavan, Phys. Rev. B 70 (2004) 134509 [selected by the Virtual Journal of Applications of Superconductivity, Nov. 1, 2004].
8. H. Khosroabadi, M. Modarreszadeh, P. Taheri, and M. Akhavan, J. of Superconductivity 17 (2004) 749.
9. H. Khosroabadi and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1863.
10. H. Khosroabadi, B. Mossalla, and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1859.
11. H. Khosroabadi, M. Modarreszadeh, P. Taheri, and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1867.
12. H. Khosroabadi, V. Daadmehr, and M. Akhavan, Physica C 384 (2003) 169.
13. H. Khosroabadi, M.R. Mohammadizadeh, and M. Akhavan, Physica B 321 (2002) 360.
14. H. Khosroabadi, M.R. Mohammadizadeh, and M. Akhavan, Physica C 370 (2002) 85.
15. H. Khosroabadi, V. Daadmehr, and M. Akhavan, Mod. Phys. Lett. B 16 (2002) 943.
16. H. Khosroabadi, M.R. Mohammadizadeh, and M. Akhavan, Iran. J. Phys. Res. 3 (2002) 59.
17. H. Khosroabadi, V. Daadmehr, and M. Akhavan, Iran. J. Phys. Res. 3 (2002) 153.
18. M.R. Mohammadizadeh, H. Khosroabadi, and M. Akhavan, Physica B 321 (2002) 301.
19. M. Maleki, H. Khosroabadi and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1871.
20. M. Mirzadeh, H. Khosroabadi and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1875.
21. M. Kariminezhad, H. Khosroabadi and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1855.
22. Z. Mokhtari, H. Khosroabadi and M. Akhavan, Phys. Stat. Sol. (c) 1 (2004) 1891.
23. M.R. Mohammadizadeh, H. Khosroabadi, H. Akbarzadeh, and M. Akhavan, in: Proceedings of the First Regional Conference on Magnetic and Superconducting Materials (MSM-99), eds. M. Akhavan, J.Jensen, and K. Kitazawa, (World Scientific, Singapore, 2000) p. 251.
Previous Research
In my MSc and PhD thesis I have been a member of groups working on different properties of high-Tc superconductors (HTSC) from the experimental and computational point of views. Here I summaries the most significant results we have obtained in these studies:
In the experimental studies we have prepared a variety of Y123 compounds with different doping, then characterization and electrical and magnetic transport properties of the samples have been investigated.
1) Some interesting scaling relations of vortex pining energy vs. magnetic filed, temperature and superconducting transition width have been found as U~H-β(1-T/Tc)q (with β≈1/3 and q≈2-3), ∆Tc~Hn and U~∆TcH-η for GdPr123 system.
2) By investigating the simultaneous effects of oxygen deficiencies and Pr doping, the suppression of superconductivity by Pr doping in GdPr123 has been explained as a combination of localization and hole filling of the carriers in the CuO2 planes.
3) By studying the mixing granular samples, it has been found that suppression of superconductivity in (1-m)Gd123-mPrBa123 is considerably weaker than (1-n)Gd123-nPr123, which seems to be useful for application point of views of mixed granular samples.
4) It has been concluded that observation of superconductivity is possible for Ba-rich Pr123, and Pr123 system with correct stoichiometry is an insulator. This is resulted from studying the Pr/Ba mis-substitution in Pr123,
5) By studying the effect of light and heavy rare earth ions and Sr and Ca cation substitutions, it has been concluded that the ionic size of rare earth elements is essential in the mechanism of suppression of superconductivity by Pr doping in these systems, and the critical concentration of Pr is increased in heavy rare earth compounds.
In the computational studies we have calculated the electronic band structure, mechanical high pressure, chemical pressure, charge transfer, phonon frequencies and electron-phonon interaction of Y123, Y124, YSCO, Gd123 and Pr123 by ab-initio simulation based on density functional theory.
1) It has been shown that the psedupotetntial method has enough accuracy to calculate the electronic structure, lattice structure, physical properties, and phonon properties of HTSC compounds.
2) It has been founded that the apical oxygen position in Y123 system is important in the hole concentration of CuO2 planes, and could be considered to optimize the Tc of these systems.
3) Mechanical pressures could effect the superconducting properties by changing the hole concentration in the CuO2 planes, confirm the charge transfer model.
4) The opposite behavior of the mechanical and chemical pressure on Tc has been explained on the contraction of CuO2-Y-CuO2 blocks under these two pressures.
5) The eigenvalues and eigenvectors of Raman Ag modes of Gd123, Y123, Y124, and Pr123 are in reasonably agreement with the experimental and other computational data.
6) The strong ionic position dependence of electronic band structure of Y123 and Y124 compounds has been interpreted as a potentially strong electron-phonon interaction in HTSC compounds.
Present research
Recent experiments have confirmed the existence of phonon softening in some of HTSCs and other superconductors (MgB2 and BKBO), which seems to be a good clue to understanding the role of electron-phonon interaction in the mechanism of superconductivity in these systems. Now, we are studying the phonon softening of Ba1-xKxBiO3 (BKBO) system.
Since only small crystals are available in the low content of potassium, we have applied Inelastic X-ray Scattering (IXS) measurement rather than neutron scattering for these measurements.
Single crystals of BKBO system (different doping value) have been grown by the electrochemical method. These samples have been characterized by the powder and Laue X-ray diffraction and SQUID magnetometry to check the crystal and superconducting properties. The phonon properties of this system have been calculated by dynamical shell model to obtain some theoretical understanding and necessary information for doing IXS measurement. The phonon spectrums of these samples have been measured by the method at the beam line 35 of super photo ring facilities (SPring- 
in Japan. From the analysis of IXS spectra we have been able to determine the acoustic and optical phonon branch for the system. Now, we are continuing our measurements to derive a conclusive result for this system.
Updated: October 20,2007
Sendai, August 2007
I hope to be successful
Hi dear Dr. Khosroabadi
I was one of students in your graduate superconduntivity course in sharif university, I am glad to see your web, it was so long time that i had not any news about you!
I want to ask you aobut phonon softening, please introduce me a good source for this topic.
i had found many answers of my questions in your class, I hope to meet you again,
best regards
Mojtaba Mazaheri
Hi Dear Mojtaba,
Nice to hear from you.
Phonon softening means the reduce of phonon ferequency by any physical parameters such as doping, temperature, phonon wave-vector Q, etc.
It could give some information about the phonon modes interactions with other quasiparticles, or collective modes in crystal.
There are many papers (just search with Phonon softening in APS), maybe you can find a Rev. paper. You can also see my weblog (post-4, Reznik et al. Nature 2006) to find an important and recent study in this filed.
Hossein