Francesco Cordero CV

# I Ricercatore

__Place and date of birth:__ Milano (Italy), 4 November 1958

__Curriculum:__

1983 Graduates in Physics at the Physics Dept. of the University of Rome “La Sapienza”.

Starts a collaboration with Prof. Cannelli and Prof. Cantelli in the Solid State Acoustics group of the Istituto di Acustica “O.M. Corbino” of CNR.

1985- Becomes researcher at the CNR, Istituto di Acustica “O.M. Corbino”.

1989- Head of the Solid State Acoustics group of the Istituto di Acustica.

1991- Member of Scientific Council of the Istituto di Acustica, reconfirmed in 1995.

1993 Member of the American Physical Society.

Member of the National Committee of ICIFUAS-10: 10th International Conference on Internal Friction and Ultrasonic Attenuation in Solids (Rome, 6-9 september 1993).

Coeditor with R. Cantelli and G. Cannelli of the Proceedings of the Conference, published in Journal of Alloys and Compounds (Elsevier).

2002 Passes the selection for Associate Professor in General Physics at the Physics Dept. of the University of Palermo, Italy

2004 Changes affiliation to the Istituto dei Sistemi Complessi of CNR

2005 PhD Degree in Engineering at the Graduate School of Pure and Applied Sciences of the University of Tsukuba, Japan. Thesis “Anelastic spectroscopy studies of high-T_{c} superconductors”, Advisor Prof. H. Mizubayashi.

2007 Senior Researcher of CNR (I Ricercatore)

2017 Changes affiliation to CNR-ISM, Istituto di Struttura della Materia

__Visits/seminars at other scientific institutions__

1988/9 Visiting scientist for 6 months at the Max-Planck-Institut, Institut für Metallforschung, Stuttgart, Germany (collaboration with Dr. M. Weller).

1994 Visits various Universities and Research Institutions in Japan, invited by Prof. M. Koiwa (Univ. of Kyoto). Seminar “Anelastic studies of high-Tc superconductors of the YBCO family” (Univ. of Tsukuba, Univ. of Sendai and Tokai University)

1999 Visits and gives lectures in various Universities in Brasil, collaboration with the Physics Dept. of UNESP, Sao Paolo, Brasil (collaboration with Prof. C. R. Grandini). Seminar on “Dynamics of atoms, polarons and defects in semiconductors and superconductors from anelastic relaxation”.

2000 Seminar “Two- and four-site tunneling of H in Nb” at the Dept. of Applied Physics, Theoretical Physics Section, Delft University of Technology, Delft, Holland, invited by Prof. M. Grifoni.-

2003 Seminar “Mobility of oxygen in high-Tc superconductors”.Physics Dept. of UNESP, Sao Paolo, Brasil, invited by Prof. C. R. Grandini.

2004 Seminar “Misure anelastiche di dinamica vetrosa in perovskiti ferroelettriche e magnetiche” (Seminario di Struttura della Materia per il Corso di Dottorato in Fisica dell’Università di Pavia, Italy, invited by Prof. A. Rigamonti)

- Seminar “Anelastic, dielectric and NMR spectroscopies in relaxor ferroelectrics” at the Martin-Luther-Universität Halle-Wittenberg, Fachbereich Physik, Halle, Germany, invited by Prof. Th. Langhammer.

2011 Seminar “New features of the phase diagrams of perovskites from anelastic and dielectric measurements”, at Dept. of Physics of the University of Warwick, UK, invited by Prof. Pam Thomas

- Seminar “Anelastic measurements in PZT: phase transitions, domain walls and defects” at the Faculty of Physics of the University of Vienna, Austria, invited by Prof. Wilfried Schranz
- Visiting Researcher at the Dept. of Physics of UFSCar, São Carlos, Brazil, 30 days/year until 2017 with CAPES Project PEV– Programa Ciencias sem Fronteiras of Prof. Paulo Sergio da Silva Jr.

Seminar “Enhancement of the piezoelectric and elastic susceptibilities at the Morphotropic Phase Boundaries between ferroelectric phases”, Dep. Fisica, Univ. São Carlos UFSCar, SP Brazil, invited by Prof. Paulo Sergio da Silva Jr.

2016 lecture “Elastic aging, fatigue and defects in antiferroelectric/ferroelectric transitions of PZT”, as part of the course Materials in Society, of the Post-Graduate Program in Materials Science and Technology, Science School at UNESP, campus Bauru, Brazil.

__Refereeing activity__

Phys. Rev. Lett., Phys. Rev. B, Phys. Rev. Materials, Nat. Commun., Physica C, J. Phys.: Condensed Matter, J. Phys. D: Appl. Phys., Solid State Commun., J. Alloys and Compounds and other journals.

__Scientific activity:__

Mainly anelastic relaxation measurements and their interpretation on perovskites and perovskite type materials (ferroelectrics, relaxors, ion conductors, superconductors, magnetic, multiferroics) on diluted metal-hydrogen and semiconductor-hydrogen alloys. Collaboration to EXAFS experiments on magnetic, superconducting and ferroelectric perovskites.

__Anelasticity from point defects__

- Calculation of the populations and anelastic and dielectric relaxation intensities of defect clusters at any concentration and with arbitrary interactions within the clusters [1,7].

__H in metals__

- Trapping of H and D by substitutional and interstitial foreign atoms in bcc metals Nb, Ta and V and hcp Y [1,4]. Hopping of H within the impurity-H complex. Influence of the elastic interactions among the complexes on H hopping dynamics [1].
- Formation of coherent tunneling systems of H, study of their geometry and of the interactions which determine their dynamics [2,4,8,13]. Study of the behaviour under stress of a four site tunnel system and application to H tunneling within substitutional-H complexes in bcc metals [8,13].

__H in semiconductors__

- Dynamics of H and D within dopant-H(D) complexes in Si and GaAs [11], hydrogenated vacancies in InP [17].

__High-T _{c} superconductors__

- Determination of the mobility of O in the CuO
_{x}planes of YBa_{2}Cu_{3}O_{6+x}in the whole range of doping [3,5,9]: hopping of isolated O atoms and O belonging to the CuO chains in different phases; hopping between the off-centre positions in the zigzag CuO chains. Oxygen ordering. - O vacancies in RuSr
_{2}GdCu_{2}O_{8}[24]. - Small polaron hopping in overdoped YBCO [10].
- Collective and tunneling-driven tilt modes of the O octahedra in slightly doped La
_{2‑x}Sr_{x}CuO_{4+}_{d}[12,15,16]. - Charge stripes in La
_{2-x}(Sr/Ba)_{x}CuO_{4}: domain walls of the cluster spin glass phase [18,20] and glassy dynamics [19]; thermally activated depinning [23]. - Mobility of interstitial O in La
_{2}CuO_{4+}_{d}[12,14].

__MgB _{2}__

- Lattice defects, effects of the anharmonic phonons on the elastic properties [22].

__Perovskites: magnetic and metal/insulator transitions__

- Glassy dynamics of the inhomogeneous ferromagnetic phase in the colossal magneto-resistance manganite La
_{1‑x}Ca_{x}MnO_{3}[21]. - Stiffening at the metal-insulator transition of RNiO
_{3}due to the loss of the dynamic Jahn-Teller distortions [33].

__Ferroelectrics__

- Revision of the phase diagrams of PZT [27,34]: new octahedral tilt transition [34], effect of tilt-polarisation coupling [36], splitting of the polar and antiferrodistortive (tilt) components of the transition to the antiferroelectric state [35,37,38].
- Giant elastic softening with aging and thermal cycling in antiferroelectric PZT [38].
- Elastic response near the morphotropic phase boundary and its relationship with the enhanced piezoelectric response [27,39].
- Phase transitions and phase diagrams of the Pb-free NBT-BT [32] and BCT-BZT [39]..
- Non-equilibrium phenomena in the relaxor ferroelectric PLZT, memory above the freezing temperature [25]. Nonpolar relaxation modes and rotational fluctuations of the O octahedra [26].
- Clarification of the piezoelectric origin of the elastic softening occurring in the ferroelectric phases and specialization to the case of enhanced piezoelectric properties near rotational instabilities of the direction of the polarization [40-42].
- Determination of the piezoelectric response of a ferroelectric ceramic from purely elastic and dielectric measurements, without need of poling [43]

__Perovskite ion conductors__

- Mobility and clustering of O vacancies in SrTiO
_{3}[28]. - Hopping and tunnelling of protons, mobility of O vacancies in BaCe
_{1-x}Y_{x}O_{3-y}[29] and their effect on the structural transitions [30] .

__Organometallic Halide Perovskites__

- Dielectric and anelastic measurements on MAPbI
_{3}: dynamics of antiferroelectrically correlated clusters in the low-temperature orthorhombic phase of MAPbI_{3}and competitive coupling with the octahedral tilt modes as cause of the lack of ordering of the MA molecules into a ferroelectric phase [44].

__Main collaborations__

- Craciun, A.M. Paoletti, G. Pennesi, CNR-ISM
- Paolone, O. Palumbo, CNR-ISC, Roma, Italy
- Galassi, CNR-ISTEC, Faenza, Italy.
- Trequattrini, R. Cantelli, Dept. Physics, University of Rome “La Sapienza”, Italy
- S. da Silva Jr., Dept. Physics, UFSCar, Sao Carlos SP, Brazil
- F. Jardim, Inst. Fisica, Universidade de Sao Paulo, Brazil
- Cannelli, Dept. Physics, University of Calabria, Arcavacata di Rende (CS), Italy
- Castellano, Dept. Structural Chemistry, Università degli Studi di Milano, Italy
- Schranz, Faculty of Physics, Universität Wien, Vienna, Austria
- Ferretti, Dept. Chemistry and Industrial Chemistry, University of Genova, Italy
- Rigamonti, M. Corti, Dept. Physics, University of Pavia, Italy.
- R. Grandini, Dept. Physics, University of Bauru, Sao Paolo, Brasil.
- Nanni, V. Buscaglia, CNR-ITAE, Genova, Italy.
- Kolodiazhni, NIMS Tsukuba, Japan.
- M. Glazer, P.M. Thomas, Dept. Physics, University of Warwick, UK

__Selected publications (out of 166)__

- Cannelli, R. Cantelli and F. Cordero, “Statistical Model for the Trapping of Interstitials by Substitutional (Interstitial) Atoms in Solids”, Phys. Rev. B
**32**, 3573 (1985). - Cannelli, R. Cantelli and F. Cordero, “Anelastic Relaxation due to the Tunneling of Trapped D in Tantalum”, Phys. Rev. B
**35**, 7264 (1987). - Cannelli, R. Cantelli, F. Cordero, M. Ferretti, and L. Verdini, “Dynamics of Oxygen in the YBa
_{2}Cu_{3}O_{7-x}basal planes by elastic-energy-loss measurements”, Phys. Rev. B**42**, 7925 (1990). - Cannelli, R. Cantelli, F. Cordero, F. Trequattrini, I.S. Anderson, and J.J. Rush, “H tunneling and trapping in Y by anelastic relaxation measurements”, Phys. Rev. Lett.
**67**, 2682 (1991). - Cannelli, R. Cantelli, F. Cordero, and F. Trequattrini, “Dynamics of oxygen and phase transitions in the 123 ceramic superconductors by anelastic relaxation measurements”, Supercond. Sci. Technol.
**5**, 247 (1992). - Cannelli, R. Cantelli, F. Cordero, “Self-Organized Criticality of the Fracture Processes Associated with Hydrogen Precipitation in Niobium by Acoustic Emission”, Phys. Rev. Lett.
**25**, 3923 (1993). - Cordero, “Anelastic (dielectric) relaxation of point defects at any concentration, with blocking effects and formation of complexes”, Phys. Rev. B
**47**, 7674 (1993). - Cannelli, R. Cantelli, F. Cordero, and F. Trequattrini, “Four-site tunneling of H trapped by substitutional Zr in Nb”, Phys. Rev. B
**49**, 15040 (1994). - Cannelli, R. Cantelli, F. Cordero, N. Piraccini, F. Trequattrini, and M. Ferretti, “Mobility and aggregation of oxygen in YBa
_{2}Cu_{3}O_{6+x}in the low-concentration limit”, Phys. Rev. B**50**, 16679 (1994). - Cannelli, R. Cantelli, F. Cordero, F. Trequattrini, and M. Ferretti, “Strong dependence on doping of a low-activation-energy relaxation process in YBa
_{2}Cu_{3}O_{6+x}: Possible polaron relaxation”, Phys. Rev. B**54**, 15537 (1996). - Cannelli, R. Cantelli, F. Cordero, E. Giovine, F. Trequattrini, M. Capizzi and A. Frova, “Quantum diffusion of deuterium in GaAs:Zn”, Solid State Commun.
**98**, 873 (1996). - Cordero, C.R. Grandini, G. Cannelli, R. Cantelli, F. Trequattrini, and M. Ferretti, “Thermally activated dynamics of the tilts of the CuO
_{6}octahedra, hopping of interstitial O and possible instability towards the LTT pahse in La_{2}CuO_{4+}_{d}”, Phys. Rev. B**57**, 8580 (1998). - Cannelli, R. Cantelli, F. Cordero and F. Trequattrini, “Tunneling of H and D in metals and semiconductors”, in
*Tunneling Systems in Amorphous and Crystalline Solids*, ed. by P. Esquinazi (Springer, Heidelberg, 1998) - Cordero, C.R. Grandini, and R. Cantelli, “Structure, mobility and clustering of interstitial O in La
_{2}CuO_{4+}_{d}in the limit of small d”, Physica C**305**, 251 (1998). - Cordero, R. Cantelli, M. Corti, M. Campana, and A. Rigamonti, “Tilt-waves dynamics of the oxygen octahedra in La
_{2}CuO_{4}from anelastic and^{139}La NQR relaxation”, Phys. Rev B**59**, 12078 (1999). - Cordero, R. Cantelli and M. Ferretti, “Tunneling driven tilt modes of the O octahedra in La
_{2‑x}Sr_{x}CuO_{4}: strong dependence on doping”, Phys. Rev. B**61**, 9775 (2000). - Cantelli, F. Cordero, O. Palumbo, G. Cannelli, F. Trequattrini, G.M. Guadalupi and B. Molinas, “Mechanisms of the semi-insulating conversion of InP by anelastic spectroscopy”, Phys. Rev. B
**62**, 1828 (2000). - Cordero, A. Paolone, R. Cantelli and M. Ferretti, “Anelastic spectroscopy of the cluster spin-glass phase in La
_{2-x}Sr_{x}CuO_{4}“, Phys. Rev. B**62**, 5309 (2000). - S. Markiewicz, F. Cordero, A. Paolone and R. Cantelli, “Cluster Spin Glass distribution functions in La
_{2-x}Sr_{x}CuO_{4}”, Phys. Rev. B**64**, 054409 (2001). - Cordero, A. Paolone, R. Cantelli and M. Ferretti, “Pinning of the domain walls of the cluster spin-glass phase in LTT La
_{2-x}Ba_{x}CuO_{4}”, Phys. Rev. B**64**, 132501 (2001). - Cordero, C. Castellano, R. Cantelli, and M. Ferretti, “Glassy dynamics of the inhomogeneous metallic phase in La
_{1-x}Ca_{x}MnO_{3}“, Phys. Rev. B**65**, 12403 (2002). - Cordero, R. Cantelli, G. Giunchi and S. Ceresara, “A search for incipient lattice instabilities in MgB
_{2}by anelastic spectroscopy”, Phys. Rev. B**64**, 132503 (2001). - Cordero, A. Paolone, R. Cantelli and M. Ferretti, “Anelastic relaxation process of polaronic origin in La
_{2-x}Sr_{x}CuO_{4}: interaction between charge stripes and pinning centers”, Phys. Rev. B**67**, 104508 (2003). - Cordero, M. Ferretti, M.R. Cimberle and R. Masini, “Formation and mobility of oxygen vacancies in RuSr
_{2}GdCu_{2}O_{8}“, Phys. Rev. B**67**, 144519 (2003). - Cordero, F. Craciun, A. Franco, D. Piazza and C. Galassi, “Memory of multiple aging stages above the freezing temperature in the relaxor ferroelectric PLZT”, Phys. Rev. Lett.
**93**, 97601 (2004). - Cordero, M. Corti, F. Craciun, C. Galassi, D. Piazza and F. Tabak, “Polar and non-polar atomic motions in the relaxor ferroelectric Pb
_{1-3x/2}La_{x}Zr_{0.2}Ti_{0.8}O_{3}(PLZT) from dielectric, anelastic and NMR relaxation”, Phys. Rev. B**71**, 94112 (2005). - Cordero, F. Craciun and C. Galassi, “Low-temperature phase transformations of PbZr
_{1−x}Ti_{x}O_{3}in the morphotropic phase-boundary region”

Phys. Rev. Lett. **98**, 255701 (2007).

- Cordero, “Hopping and clustering of oxygen vacancies in SrTiO
_{3}by anelastic relaxation”

Phys. Rev. B **76**, 172106 (2007).

- Cordero, , F. Craciun, F. Deganello, V. La Parola, E. Roncari and A. Sanson “Hydrogen tunneling in the perovskite ionic conductor BaCe
_{1−x}Y_{x}O_{3−}_{d}“

Phys. Rev. B **78**, 054108 (2008).

- Cordero, F. Trequattrini, F. Deganello, V. La Parola, E. Roncari and A. Sanson, “Effect of O vacancies on the Young’s modulus of the BaCe
_{1−x}Y_{x}O_{3−}_{d}perovskite”

Appl. Phys. Lett. **94**, 181905 (2009).

[31] F. Cordero, F. Trequattrini, F. Deganello, V. La Parola, E. Roncari and A. Sanson “Effect of doping and oxygen vacancies on the octahedral tilt transitions in the BaCeO_{3} perovskite”

Phys. Rev. B **82**, 104102 (2010).

[32] F. Cordero, F. Craciun, F. Trequattrini, E. Mercadelli and C. Galassi “Phase transitions and phase diagram of the ferroelectric perovskite (Na_{0.5}Bi_{0.5})_{1−x}Ba_{x}TiO_{3 }by anelastic and dielectric measurements”

Phys. Rev. B **81**, 144124 (2010).

[33] F. Cordero, F. Trequattrini, V. B. Barbeta, R. F. Jardim, and M. S. Torikachvili, “Anelastic spectroscopy study of the metal-insulator transition of Nd_{1−x}Eu_{x}NiO_{3}”

Phys. Rev. B **84**, 125127 (2011).

[34] F. Cordero, F. Trequattrini, F. Craciun and C. Galassi, “Octahedral tilting, monoclinic phase and the phase diagram of PbZr_{1−x}Ti_{x}O_{3}”

- Phys.: Condens. Matter
**23**, 415901 (2011).

[35] F. Cordero, F. Trequattrini, F. Craciun and C. Galassi, “Merging of the polar and tilt instability lines near the respective morphotropic phase boundaries of PbZr_{1−x}Ti_{x}O_{3}”

Phys. Rev. B **87**, 094108 (2013).

[36] F. Cordero, F. Craciun, F. Trequattrini and C. Galassi, “Effects of coupling between octahedral tilting and polar modes on the phase diagram of the ferroelectric perovskites PbZr_{1}_{‑}_{x}Ti_{x}O_{3} and (Na_{1/2}Bi_{1/2})_{1}_{–}_{x}Ba_{x}TiO_{3}”

Phase Transit. **87**, 255 (2014)

[37] F. Cordero, F. Craciun, F. Trequattrini, C. Galassi, P.A. Thomas, D.S. Keeble and A.M. Glazer, “Splitting of the transition to the antiferroelectric state in PbZr_{0.95}Ti_{0.05}O_{3} into polar and antiferrodistortive components”

Phys. Rev. B **88**, 094107 (2013).

[38] F. Cordero, F. Trequattrini, F. Craciun, and C. Galassi

“Effects of aging and annealing on the polar and antiferrodistortive components of the antiferroelectric transition in PbZr_{1−x}Ti_{x}O_{3}”

Phys. Rev. B **89**, 214102 (2014).

[39] F. Cordero, F. Craciun, M. Dinescu, N. Scarisoreanu, C. Galassi, W. Schranz, and V. Soprunyuk

“Elastic response of (1−x)Ba(Ti0.8Zr0.2)O3 – x(Ba0.7Ca0.3)TiO3 (x=0.45–0.55) and the role of the intermediate orthorhombic phase in enhancing the piezoelectric coupling”

Appl. Phys. Lett. **103**, 122903 (20).

[40] F. Cordero

“Elastic Properties and Enhanced Piezoelectric Response at Morphotropic Phase Boundaries”

Materials (Basel) **8**, 8195-8245 (2915).

[41] F. Cordero, H.T. Langhammer, T. Müller, V. Buscaglia and P. Nanni

“Rotational instability of the electric polarization and divergence of the shear elastic compliance”

Phys. Rev. B **93**, 064111 (2016).

[42] F. Cordero, F. Craciun, F. Trequattrini and C. Galassi

“Piezoelectric softening in ferroelectrics: Ferroelectric versus antiferroelectric PbZr_{1−x}Ti* _{x}*O

_{3}”

Phys. Rev. B **93**, 174111 (2016).

[43] F. Cordero

“Quantitative evaluation of the piezoelectric response of unpoled ferroelectric ceramics from elastic and dielectric measurements: Tetragonal BaTiO_{3}”

- Appl. Phys.
**123**, 094103 (2018).

[44] F. Cordero, F. Craciun, F. Trequattrini, P. Imperatori, A. M. Paoletti and G. Pennesi

“Competition between Polar and Antiferrodistortive Modes and Correlated Dynamics of the Methylammonium Molecules in MAPbI_{3} from Anelastic and Dielectric Measurements”

- Phys. Chem. Lett.
**9**, 4401-4406 (2018).

__101 communications at international conferences (18 invited)__

__Research Projects__

1989 -1992 Progetto Finalizzato CNR “Tecnologie Superconduttive e Criogeniche” coord. A. Barone, Unit CNR-Ist. Acustica (resp. G. Cannelli).

1993 Progetto Speciale INFM-GNSM “Idrogeno in semiconduttori cristallini” coord. A. Frova, Unit CNR-Ist. Acustica.

1994 Progetto Speciale INFM-GNSM “Dinamica molecolare e proprietà elettroniche in fullereni” coord. L. Pietronero, Unit CNR-Ist. Acustica.

1995 Progetto Speciale INFM-GNSM “High Tc superconductors made by metal heterostructures at the atomic limit” coord. A. Bianconi, Unit CNR-Ist. Acustica.

1998-2001 PRA-SPIS (Advanced Research Project INFM) “Spectroscopic Studies of Pseudo-Gaps in High-Tc Superconductors”, coord. R. Cantelli, Unit Univ. Roma I (resp. R. Cantelli)

2001-2002 Cooperation Agreement CNR-CNPq “Lattice fluctuations amd mobility of interstitial oxygen in cuprate superconductors by anelastic spectroscopy”; Italian resp. F. Cordero, Brasilian resp. C.R. Grandini.

2003-2005 FIRB (Italian Ministry of University and Research) “New Materials and Mechanisms of Superconductivity in Fullerenes” coord. L. Pietronero; Unit CNR-ISC ARTOV.

2006-2009 FISR (Italian Ministry of University and Research) “Fuel cells with polymeric and ceramic electrolytes: prototypes and new materials”, subcontractor in the unit CNR-IENI (resp. M. Fabrizio).

2008-2009 CNR RSTL “Ferroelectric and relaxor materials”

2011-2014 COST MP0904 Action Simufer “Single and multiphase ferroics and multiferroics with restricted geometries” coord. by L. Misoseriu, participant

2014-2017 CAPES Project PEV– Programa Ciencias sem Fronteiras (Brazil) n. 88881.062225/2014-01 of Prof. Paulo Sergio da Silva Jr: visiting Researcher 30 days/year at the Dept. of Physics of UFSCar, São Carlos, Brazil, and 1 year stay at ISC of the Brazilian PhD student J.C.C. Albornoz Diaz.