ICAME 2005 (eBook)

Title page 2
Copyright page 3
Table of contents 4
Synchrotron Mössbauer retlectometry using stroboscopic detection 
12 
1 Introduction 12
2 The stroboscopic synchrotron Mössbauer reflectometry 13
3 Results and discussion 15
4 Conclusion 17
Reference 17
Synthesis and characterisation of the Fe(II-III) hydroxy-formate green rust 
19 
1 Introduction 19
2 Materials and methods 20
3 Results and discussion 20
3.1 Eh and pH vs time curves 20
3.2 Analyses of the precipitate at various oxidation times 21
4 Conclusion 23
References 23
Monitoring structural transformation of hydroxy-sulphate green rust in the presence of sulphate reducing bacteria 
25 
1 Introduction 25
2 Experimental methods 26
3 Results and discussion 27
3.1 Bioreduction of lepidocrocite 27
3.2 Reactivity of GR2 with SRB 27
4 Conclusion 29
References 29
In situ 119Sn Mössbauer spectroscopy used to study lithium insertion in c-Mg2Sn 
30 
1 Introduction 30
2 Experimental 31
3 Results and discussions 31
4 Conclusions 33
References 33
In situ 119Sn Mössbauer spectroscopy study of Sn-based electrode materials 
34 
1 Introduction 34
2 Experimental 35
3 Results and discussion 35
4 Conclusion 38
References 38
Influence of Cu and Ni on the morphology and composition of the rust layer of steels exposed to industrial environment 
40 
1 Introduction 41
2 Experimental procedures 41
3 Results and discussion 42
4 Conclusions 46
References 47
Mossbauer investigations of corrosion environment influence on Fe valence states in oxide films of zirconium alloys 
48 
1 Introduction 48
2 Technique of alloy preparation 48
3 Experimental results 49
3.1 Spectra obtained after corrosion of alloys in water with Band Li 49
3.2 Corrosion in air 51
3.3 Corrosion in oxygen 51
3.4 Corrosion in autoclave 52
4 Conclusion 52
References 52
Atmospheric corrosion of mild steel in Oman 
53 
1 Introduction 53
2 Samples preparation and experimental methods 54
3 Results and discussion 54
4 Conclusions 57
References 58
Structural transformations in lithiated Mn2Sb electrodes probed by Mössbauer spectroscopy and X-ray diffraction 
59 
1 Introduction 59
2 Experimental 60
3 Results and discussions 61
3.1 Sample A 61
3.2 Samples B, C, D, E and F 62
3.3 Sample G 63
3.4 Phase formation processes 63
4 Conclusions 64
References 65
Mössbauer study on LiFeP04 cathode material for lithium ion batteries 
66 
1 Introduction 66
2 Experimental section 68
3 Results and discussion 68
4 Conclusion 70
References 70
Evaluation of structural and electrochemical properties of the MnSb-Li system as anode for Li-ion batteries 
72 
1 Introduction 72
2 Exper imental aspects 73
3 Results and discussions 74
4 Conclusions 76
References 77
Iron ions in ZSM-5 zeolite: Fe3+ in framework, Fe2+in extra-framework positions in catalytic N2O decomposition 
78 
1 Introduction 78
2 Experimental 79
2.1 Sample preparation 79
2.2 Mossbauer measurements 79
2.3 Catalytic performance 79
3 Results and discussion 80
3.1 57Fe isomorphous substitution 80
3.2 Ion exchange of Fe2+ 80
3.3 Catalytic performance 81
3.4 Effect of N2O as reflected in the in situ spectra 81
References 82
119Sn Mössbauer study of nickel-tin anodes for rechargeable lithium-ion batteries 
84 
1 Introduction 84
2 Experimental 85
3 Results and discussion 85
4 Conclusions 89
References 89
Phase composition and distribution of corrosion products grown on galvanised steel in contact with hot water 
90 
1 Introduction 90
2 Experimental details 91
3 Results and discussion 91
References 95
Mechanosynthesis and characterisation of the Li-Sn system 
96 
1 Introduction 96
2 Experimental 97
3 Results and discussion 97
4 Conclusions 99
References 100
Chemical stability of hydroxysulphate green rust synthetised in the presence of foreign anions: carbonate, phosphate and silicate 
101 
1 Introduction 101
2 Materials and methods 102
3 Transformation of hydroxysulphate green rust and role of the carbonate species 102
4 Stabilization of hydroxysulphate green rust by phosphate and silicate anions 104
5 Conclusion 105
References 105
Mössbauer characterization of calcium-ferrite oxides prepared by calcining FezO3 and CaO 
106 
1 Introduction 106
2 Experimental 107
3 Results and discussion 107
References 109
Relative Lamb-Mössbauer factors of tin corrosion products 
111 
1 Introduction 111
2 Experimental 112
3 Results 113
3.1 Hyperfine parameters 113
3.2 Lamb-Mössbauer factor ({-factor) 113
4 Conclusions 114
References 114
Study of the electrochemical properties in substituted Li2Ti3O7 ramsdellite 
115 
1 Introduction 115
2 Experimental 116
3 Results and discussion 118
4 Conclusion 118
References 118
A Mössbauer spectroscopic study of an industrial catalyst for dehydrogenation of etylbenzene to styrene 
120 
1 Introduction 120
2 Experimental 122
3 Results and discussion 123
References 125
Generation of long-lived isomeric states via bremsstrahlung irradiation 
127 
1 Introduction 127
2 Mössbauer spectroscopy with higher resolution 128
3 Excitation by bremsstrahlung 129
4 Experiment and results 130
5 Gravitational impact 131
References 132
Magnetic and thermal Mössbauer effect scans: a new approach 
133 
1 Introduction 134
2 Experiments 135
3 Conclusion 138
References 138
Velocity calibration for in-situ Mössbauer data from Mars 
139 
1 Introduction 140
2 The MERView program 140
3 Velocity calibration 141
4 Conclusion 143
References 144
A simple model to extract hyperfine interaction distributions from Mössbauer spectra 
145 
1 Introduction 145
2 The model 146
3 Examples of results 147
4 Discussion and conclusions 148
References 148
Dynamical beats of forward-scattered resonant synchrotron radiation as a nuclear polariton effect 
149 
1 Introduction 149
2 Contracting nuclear exciton 150
3 Dynamical beats as a polariton effect 151
References 152
Multipurpose spectrometer TERLAB for depth selective investigation of surface and multilayer 
154 
1 Introduction 154
2 Block-diagram of spectrometer 155
3 Investigation procedure 156
4 Numerical simulation of analytical signals 157
5 Fitting of experimental data 157
6 Example 160
References 160
Automated Mössbauer spectroscopy in the field and monitoring of fougerite 
161 
1 Introduction 162
2 The instrument and experimental setup 162
2.1 The instrument MIMOS II 162
2.2 Experimental setup for in-field applications 162
3 First results 165
References 165
New in-beam Mössbauer spectroscopy stationat the Budapest Research Reactor 
166 
1 Introduction 166
2 The new in-beam Mössbauer facility 
167 
3 Expected performance of the system and fields of applications 167
Appendix 169
References 170
Effects of trapped electrons on the line shape in emission Mössbauer spectra 
171 
1 Introduction 171
2 Materials and methods 172
3 Results and discussion 172
4 Conclusions 175
References 175
Development of a new method of the analysis mossbauer spectra of systems with nuclear heterogeneity 
176 
1 Introduction 176
2 New method of the analysis mossbauer spectra 178
3 Application of the developed method 180
4 Conclusion 181
References 181
Radio-frequency controllable quantum interference in Mössbauer spectroscopy 
182 
1 Introduction 182
2 Resonant fluorescence of Mössbauer radiation in the regime of RF resonance in excited nuclear state 183
References 185
Radio-frequency Mössbauer spectra of the "easy"-plane type magnetic system (FeBO3) 
186 
1 Introduction 186
2 Physical model 187
3 Features of theoretical spectra 189
4 Experimental results 190
5 Conclusion 190
References 190
ERRATUM Radio-frequency Mössbauer spectra of the "easy"-plane type magnetic system (FeBO3) 191
Advances in constant-velocity Mössbauer instrumentation 
193 
1 Introduction 193
2 Constant-velocity strategy 194
3 General design considerations and operation 195
4 Experimental results and further work 196
References 197
Optimization of the filter technique 
198 
References 202
Experimental observation of vibrations produced by pulsed laser beam in MgO:57Fe 
203 
1 Mössbauer spectroscopy, laser-induced effects 203
References 207
Characterization of products emanating from conventional and microwave energy roasting of chalcopyrite (CuFeS2) concentrate 
208 
1 Introduction 208
2 Experimental 211
2.1 Materials and roasting process 211
2.2 Characterisatio n techniques 211
3 Results and discussion 212
4 Conclusions 213
References 213
Mössbauer analysis and magnetic properties of Invar Fe-Ni-C and Fe-Ni-Mn-C alloys 
214 
1 Introduction 214
2 Experimental 215
3 Results and discussion 215
4 Conclusions 220
References 220
Phase coexistence in mechanicallly alloyed iron-manganese powders 
221 
1 Introduction 221
2 Experimental 223
3 Results and discussion 224
References 225
Synthesis and characterization of Fe3AIC0.5 by mechanical alloying 
227 
1 Introduction 227
2 Experimental procedure 229
3 Results and discussions 229
4 Conclusions 232
References 233
Mössbauer and X-ray diffraction characterization of Fe60Al40 coatings prepared by thermal spraying 
234 
1 Introduction 234
2 Experimental method 235
3 Results and discussion 236
4 Conclusion 240
References 240
Formation of Mn-doped iron silicldes by ball milling 
241 
1 Introduction 241
2 Experimental 243
3 Results and discussion 244
4 Conclusions 245
References 245
Calculation of absolute concentrations and probability of resonant absorption for iron-bearing precipitates in zirconium alloys 
247 
1 Introduction 247
2 Theoretical dependence 248
3 Results of investigations 250
4 Discussion of results 252
5 Conclusions 253
References 253
Mössbauer spectroscopy and X-ray diffraction study of the Fe3-xTixAI ternary alloys 
254 
1 Introduction 254
2 Experimental 255
3 Results and discussion 256
4 Conclusions 257
References 257
ERRATUM Mössbauer spectroscopy and X-ray diffraction study of the Fe3-xTixAI ternary alloys 259
Complexes based on ethylene- and propylene-bridged-pentadentate-Fe(lII)-units allow interplay between magnetic centers and multistability investigated by Mdssbauer spectroscopy 
260 
1 Introduction 260
2 Experimental 261
2.1 Ligand: 261
2.2 Precursor 261
2.3 Multinuclear complexes 262
2.4 Mössbauer spectroscopy 262
3 Results and discussion 263
References 266
Hyperfine interactions, structure and magnetic properties of nanocrystalline Co-Fe-Ni alloys preparedby mechanical alloying 
267 
1 Introduction 267
2 Experimental details 268
3 Results and discussion 268
4 Conclusions 271
References 272
Metallurgical behaviour of iron in brass studied using Mössbauer spectroscopy 273
1 Introduction 273
2 Experimental 273
3 Result and discussion 274
4 Conclusion 277
References 277
Chemical tuning of high-spin complexes based on 3-and 4-hydroxy-pentadentate-Fe (III) complex-units investigated by Mössbauer spectroscopy 
278 
1 Introduction 278
2 Experimental 279
2.1 Ligands 279
2.2 Precursors 279
2.3 Multinuclear complexes 279
2.4 Mössbauer spectroscopy 281
3 Results and discussion 281
4 Conclusion 284
References 284
Determination of the chromium concentration of phase decomposition products in an aged duplex stainless steel 
285 
1 Introduction 285
2 Experimental 286
3 Results and discussion 287
3.1 Cr concentration of the iron-rich phase 287
3.2 Cr concentration of the chromium-rich phase 289
4 Conclusion 291
References 291
Mössbauer spectroscopy study of mechanically alloyed Fe203-(Al, Co and WC) systems 
292 
1 Introduction 292
2 Materials and methods 293
3 Results and discussion 294
4 Conclusions 297
References 297
Mössbauer study of the invar Fe-Ni and Fe-Ni-C alloysin magnetic field 
298 
1 Introduction 298
2 Experimental details 299
3 Results and discussions 300
4 Conclusions 301
References 302
Mössbauer study of Mg-Ni(Fe) alloys processedas materials for solid state hydrogen storage 
303 
1 Introduction 304
2 Experimental 304
3 Results and discussions 304
4 Conclusions 308
References 309
Characterizing the ordering of thermomechanically processed high-Si steel by Mdssbauer effect techniques 
310 
1 Introduction 310
2 Experimental 311
3 Results and discussion 312
4 Conclusions 313
References 313
Effect of hydrogen on interatomic bonds in austenitic steels 
314 
1 Introduction 314
2 Experimental 315
3 Results and discussion 315
3.1 Debay temperature 315
4 Conclusions 318
References 318
Quadrupole interactions at 57Fe and 119Sn in 3d-metal antimonides 
319 
1 Introduction 319
2 Results and discussion 320
2.1 Fe1+xSb system 320
2.2 Ni1 +xSb and Co1+xSb system 320
2.3 (Ni1-yFey)Sb solid solution 321
3 Conclusions 322
References 322
Effect of N-substitution in multinuclear complexes allows interplay between magnetic states and multistability in vestigated by Mössbauer spectroscopy 
323 
1 Introduction 323
2 Experimental 324
2.1 Ligands 324
2.2 Precursors 324
2.3 Nonanuclear complexes 325
2.4 Mössbauer spectroscopy 325
3 Results and discussion 325
References 328
Mössbauer, X-ray diffraction and magnetization studies of Fe-Mn-AI-Nb alloys prepared by highenergy ball milling 
329 
1 Introduction 329
2 Experimental 330
3 Results and discussion 330
3.1 Fe60Mn10Al20Nb10 powders milled for 12,24 and 36 h 330
3.2 (Fe60Mn10AI30)100-xNbx system with x = 0, 5 and 10 milled for 12 h 334
4 Conclusions 334
References 334
CEMS study on diluted magneto titanium oxide films prepared by pulsed laser deposition 
336 
1 Introduction 336
2 Experimental 338
3 Results and discussion 338
4 Summary 342
References 342
Elastic properties of filled-Skutterudite compounds probed by Mössbauer nuclei 
343 
1 Introduction 344
2 Experimental procedure 344
3 Experimental results 344
4 Summary 346
References 347
Mössbauer spectroscopy study of spin structure and its in-field andtemperature dynamics in B2 ordered Fe(AI) alloys 
348 
1 Introduction 348
2 Experimental 349
3 Resultsanddiscussion 349
References 351
57Fe Mössbauer spectra and magnetic data from the kagomé antiferromagnet H3O-jarosite 
353 
References 357
Structural evolution of ball-milled permalloy 
358 
1 Introduction 358
2 Experimental 359
3 Phase evolution in milled elemental powder 359
4 Atomic order in milled ribbon 361
5 Temperature investigations 362
6 Summary 363
References 363
57Fe Mössbauer and magnetic studies of DyFe12-xTax compounds 
364 
1 Introduction 364
2 Experiment al 365
3 Results and discussion 366
References 368
Gol'danskii-Karyagin effect and induced fields in rare earth-transition metal stannides 
370 
1 Introduction 370
2 Experimental 371
3 Results 371
4 Discussion 373
References 374
Thermal equilibrium defects in iron-based alloys 
375 
1 Introduction 375
2 Experimental and results 376
3 Final conclusion 379
References 380
Study of the [Fe(OMe)(dpm)2]2 dimer in the presence of a magnetic field by using Mössbauer spectroscopy 
381 
References 385
Distribution of electric and magnetic hyperfine fields in Fe-rich gallo-germanates 
386 
1 Introduction 386
2 Experimental results 387
3 Discussion 388
4 Conclusions 390
References 390
Mössbauer effect studies on the formation of iron oxide phases synthesized via microwave-hydrothermal route 
391 
1 Introduction 392
2 Experimental 392
3 Results and discussion 393
References 396
Magnetic behavior of the bond random mixed compound FE(BRxl1 - x )2(x = 0.9) with Mössbauer spectroscopy 
397 
1 Introduction 397
2 Experimental 398
3 Results and discussion 398
4 Summary 401
References 401
Mössbauer studies of the layered compound 1T-TAS2 
402 
1 Introduction 402
2 Experimental arrangement 403
3 Experimental results 406
4 Conclusion 407
References 407
57Fe Mössbauer spectroscopy studies of Sr2Fe1-xCrxMo1-xWxO6 double perovskite compounds 
408 
1 Introduction 408
2 Experimental 409
3 Results and discussion 409
4 Conclusions 412
References 412
Magnetic and Mössbauer study of Mg0.9Mn0.1CrxFe2-xO4 ferrites 
413 
1 Introduction 413
2 Experimental procedures 414
3 Results and discussion 415
References 418
Theoretical investigation of Mössbauer hyperfine interactions in ordered FeNi and disordered Fe-Ni alloys 
420 
1 Introduction 420
2 Theoretical method 421
3 Results and discussion 421
References 424
Tin-doped spinel-related oxides of composition M3O4 (M = Mn, Fe, Co) 
425 
1 Introduction 425
2 Experimental 426
3 Results and discussion 426
4 Conclusions 429
References 429
Mössbauer study of 1/8 anomaly in La2-xBaxCuO4 
430 
1 Introduction 
430 
2 Experimental 431
3 Results and discussion 431
References 433
237Np and 57Fe Mössbauer study of NpFeGa5 
434 
1 Introduction 434
2 Experimental 435
3 Results and discussion 435
4 Conclusion 437
References 437
The study of superexchange interaction of ordered Li0.5Fe1.0Rh1.5O4 
439 
1 Introduction 439
2 Experiments 440
3 Results and disscussion 
440 
Referen ces 442
Amorphous Fe-Mg alloy thin films: magnetic properties and atomic vibrational dynamics 
443 
1 Introduction 443
2 Experimental 444
3 Results and discussion 444
3.1 Magnetism 444
3.2 Vibrational dynamics 447
References 447
Neutron diffraction and Mössbauer study on FeGaxCr2- xS4 
449 
1 Introduction 449
2 Experiments 451
3 Results and discussion 451
4 Conclusion 453
References 453
57Fe Mössbauer spectroscopy on the cyclic spin-cluster Fe6(tea)6(CH3OH)6 
454 
1 Introduction 454
2 Experimental results 455
3 Conclusion 457
References 457
Mössbauer spectroscopic study of half-Heusler compounds 
458 
1 Introduction 458
2 Experimental 459
3 Results and discussion 459
References 463
Mössbauer study of the martensitic transformation in a Ni-Fe-Ga shape memory alloy 
464 
1 Introduction 464
2 Experimental methods 465
3 Results and discussion 466
4 Conclusions 466
References 467
The BM5Se9 phases: Mössbauer studies of the superconductors and the ferromagnets 
468 
1 Introduction 468
2 Experimental 469
3 Results 470
3.1 Sn0.94Gao.06Nb4.70V0.30Se9 (ferromagnet) 
470 
3.2 SbNb5Se9 (superconductor) 
471 
4 Discussion 472
5 Conclusions 472
References 472
Systematic study of mechanical deformation on Fe3AlxSi1-x powders by Mössbauer spectroscopy 
473 
1 Introduction 473
2 Experimental 475
3 Results and discussion 
476 
3.1 Annealed samples 476
3.2 Deformed samples 477
4 Conclusions 478
References 478
Magneto-crystalline properties of BaFe12-2xMxSnxO19 (M = Sn, Ni, Zn) ferrite powders 
479 
1 Introduction 480
2 Experimental 480
3 Results and discussion 481
4 Conclusions 485
References 486
Mössbauer studies of the re-entrant spin-glass behaviour of Fe-AI alloys 
487 
References 490
Mössbauer study on the magnetic field-induced insulator-to-metal transition in perovskiteEU0.6Sr0.4MnO3 
491 
1 Introduction 491
2 Experiments 493
3 Results and discussions 493
References 496
57Fe and 151Eu Mössbauer studies of magnetoresistive Europium based cobalt perovskites 
497 
1 Introduction 497
2 Experimental 498
3 Results and discussion 499
References 502
Creation of ferromagnetic properties of V-Fe and Zr-Fe alloys by hydrogen absorption 
503 
1 Introduction 503
2 Experimental details 504
3 Results and discussion 505
3.1 V1-yFeyHx system 
505 
3.2 Zr1-yFeyHx system 
506 
4 Conclusion 507
References 507
Magnetic and structural properties of the Nd2(Fe100-xNbx)14B system prepared by arc melting 
508 
1 Introduction 508
2 Experimental procedure 509
3 Results and discussion 510
4 Conclusions 512
References 513
Mössbauer spectroscopic studies of Fe-20 wt. % Cr ballmilled alloy 
514 
1 Introduction 514
2 Experimental procedures 515
3 Result s and discussions 516
3.1 X-ray diffraction 516
3.2 Particle morphology 516
3.3 Mössbauer spectroscopy 
517 
3.3.1 Preferential diffusion of Chromium atoms 521
4 Conclusion 521
Reference 521
Magnetotransport and magnetic properties of snlfospinels ZnxFe1-xCr2S4 
522 
1 Introduction 522
2 Experimental 523
3 Results and discussion 524
4 Conclusion 527
References 527
Antiferromagnetic TiFe2 in applied fields: experiment and simulation 
528 
1 Introduction 528
2 Model calculations 529
3 Discussion 531
4 Conclusions 532
References 532
Determination of Lamb-Mössbauer factors and lattice dynamics in some nitroprusside single crystals 
533 
1 Introductlon 533
2 Experimental details and calculations 534
3 Results and discussion 535
4 Conclusions 536
References 537
Temperature dependent Mössbauer and neutron diffraction studies of CuxFe1-xCr2S4 compounds 
538 
1 Introduction 538
2 Experiments 539
3 Results and discussion 540
4 Conclusion 543
Reference 543
Mössbauer effect study of the decagonal quasicrystal Al65Co15Cu20 
544 
1 Introduction 544
2 Experimental procedure 545
3 Results and discussion 545
4 Conclusions 547
References 547
Absence of charge fluctuations of europium in metallics ingle crystals of EuCu2Si2 
548 
1 Introduction 548
2 Experimental procedure 549
3 Results and discussion 550
4 Conclusions 552
References 552
Debye temperature and magnetic ordering in KxBa1-xFe2S3 
553 
References 556
Mössbauer investigation of Fe0.51n1.5S3 
557 
References 560
Mössbauer study of Fe0.05Ni0.95Cl2 
561 
1 Introduction 561
2 Experimental 563
3 Results and discussions 564
References 565
Formation of Fei-B pairs in silicon at high temperatures 
566 
1 Introduction 566
2 Experimental 567
3 Results and analysis 567
4 Discussion and conclusions 569
References 569
Identification of substitutional and interstitial Fe in 6H-SiC 
570 
1 Introduction 
570 
2 Experimental 571
3 Results and discussion 571
References 574
Mössbauer and magnetic study of Mn2+ - and Cr3+ -substituted spinel magnesioferrites of the composition Mg1-xMnxFe2-2xCr2xO4 
575 
1 Introduction 575
2 Experimental 576
3 Results and discussion 576
References 579
Critical behavior of La0.67-y (Sr, Ba, Ca)0.33+yMn1-xSnxO3(x=0.01, 0.02, y=0, 0.07) perovskites 
580 
1 Introduction 580
2 Experimental 581
3 Results and discussion 581
4 Conclusions 
584 
References 585
Magnetization and magnetostriction studies of TbFeCoNFeCo multilayers 
586 
1 Introduction 586
2 Experimental procedures 587
3 Results and discussion 587
4 Conclusion 591
References 591
Thickness dependence of the magnetic anisotropy of Fe layers separated by Al 
592 
References 596
CEMS characterisation of Fe/hjgh-k, oxide interfaces 
597 
1 Introduction 597
2 Experimental 598
3 Results and discussion 598
4 Conclusions 600
References 601
Hematite thin films: growth and characterization 
602 
1 Introduction 602
2 Experimental details 603
3 Results and discussion 604
4 Conclusions 608
References 609
Mössbauer and optical investigation of Co3-xFexO4 thin films grown by sol-gel process 
610 
1 Introduction 610
2 Experimental 611
3 Results and discussion 612
4 Conclusion 615
References 616
Mösshauer spectroscopical investigation of the exchange biased Fe/MnF2 interface 
617 
1 Introduction 618
2 Samplepreparation andcharacterisation 618
3 SQUID magnetometry results 620
4 CEMS results and discussion 620
5 Summary 622
References 623
Intermixing during epitaxial growth and Mössbauer spectroscopy with probe layers 
624 
References 627
Mössbauer and SEM study of Fe-AI film 
628 
1 Introduction 628
2 Experimental methods 629
3 Results and discussion 630
References 632
Light-induced spin crossover observed for a Fe(II) complex embedded in a Nation membrane 
634 
1 Introduction 634
2 Results 635
3 Conclusion 637
References 637
Author Index to Volumes 167/1-3, 168/1-3 and 169/1-3 (2006) 
638 

"Influence of Cu and Ni on the morphology and composition of the rust layer of steels exposed to industrial environment (p. 739-740)

Abstract

Four samples of steels with alloying elements were exposed to an industrial environment during 1,955 days, aiming to elucidate the effect of the alloying elements Cu and Ni on the resistance of weathering steels to corrosion processes. The samples were characterized with optical microscopy, scanning electron microscopy (SEM), powder X-ray diffraction (XRD), saturation magnetization measurements and with energy dispersive (EDS), infrared, Mossbauer and Raman spectroscopies. All the steels originated orange and dark corrosion layers; their thicknesses were determined from the SEM images.

EDS data of such rust layers showed that the alloying element content decreases from the steel core towards the outer part of the rust layer. Moreover, in the dark rust layer some light-gray regions were identified in the Wand Cu-alloy steel, where relatively higher Cr and Cu contents were found. XRD patterns, infrared, Raman and Mossbauer spectra (298, 110 and 4 K) indicated that the corrosion products are qualitatively the same, containing lepidocrocite (yFeOOH; hereinafter, it may be referred to as simply L), goethite (aFeOOH; G), feroxyhite (bFeOOH; F), hematite (aFeZ03; H) and magnetite (Fe304; M) in all samples; this composition does not depend upon the steel type, but their relative concentrations is related to the alloying element. Mossbauer data reveal the presence of (super)paramagnetic iron oxides in the corrosion products. Saturation magnetization measurements suggest that feroxyhite may be an occurring ferrimagnetic phase in the rust layer.

Key words low alloy steels iron oxides -corrosion

1 Introduction

The knowledge of the resistance of steels to corrosion is very important for metallurgy industries. The weathering steel, also known as low alloy steel, does contain small proportions of alloying elements, typically not more than I mass% of, for instance, Cu, Cr, Ni or P. In some cases, the weathering steel is preferable to the mild steel, due to the formation of an adherent and compact rust layer known as "patina," which tends to decrease its corrosion rate. The formation of the patina is favored by the presence of alloying elements, and also of SOz and humid-dry cycles of the industrial atmosphere.

The exposition time to such conditions tends to increase the patina layer. According to the literature, the alloying elements tend mainly to decrease the size of the corrosion thickness [I, 2]. However, in those works, contents of the alloying elements were used in higher proportions than that of the weathering steel [3-6], and they were combined with other elements [7], making it difficult to infer about their individual contribution to the resistance of the steel to corrosion. The main objective of this work was to study specifically the role of Cu and Ni as alloying elements on the morphology and composition of the rust layer of the corresponding weathering steels."