Changeset 2277 for Tutorials/StackingFaults-I/Stacking Faults-I.htm
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Tutorials/StackingFaults-I/Stacking Faults-I.htm
r2260 r2277 16 16 {font-family:Tahoma; 17 17 panose-1:2 11 6 4 3 5 4 4 2 4;} 18 @font-face 19 {font-family:Cambria; 20 panose-1:2 4 5 3 5 4 6 3 2 4;} 18 21 /* Style Definitions */ 19 22 p.MsoNormal, li.MsoNormal, div.MsoNormal … … 113 116 font-family:"Times New Roman",serif;} 114 117 p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph 115 {margin-top:0in;116 margin-right:0in;117 margin-bottom:0in;118 margin-left:.5in;119 margin-bottom:.0001pt;120 font-size:12.0pt;121 font-family:"Times New Roman",serif;}122 p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst123 {margin-top:0in;124 margin-right:0in;125 margin-bottom:0in;126 margin-left:.5in;127 margin-bottom:.0001pt;128 font-size:12.0pt;129 font-family:"Times New Roman",serif;}130 p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle131 {margin-top:0in;132 margin-right:0in;133 margin-bottom:0in;134 margin-left:.5in;135 margin-bottom:.0001pt;136 font-size:12.0pt;137 font-family:"Times New Roman",serif;}138 p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast139 118 {margin-top:0in; 140 119 margin-right:0in; … … 182 161 mso-style-link:"HTML Preformatted"; 183 162 font-family:"Courier New";} 163 p.msonormal0, li.msonormal0, div.msonormal0 164 {mso-style-name:msonormal; 165 margin-right:0in; 166 margin-left:0in; 167 font-size:12.0pt; 168 font-family:"Times New Roman",serif;} 184 169 span.HeaderChar 185 170 {mso-style-name:"Header Char"; … … 198 183 mso-style-link:"Balloon Text"; 199 184 font-family:"Tahoma",sans-serif;} 185 p.msolistparagraphcxspfirst, li.msolistparagraphcxspfirst, div.msolistparagraphcxspfirst 186 {mso-style-name:msolistparagraphcxspfirst; 187 margin-top:0in; 188 margin-right:0in; 189 margin-bottom:0in; 190 margin-left:.5in; 191 margin-bottom:.0001pt; 192 font-size:12.0pt; 193 font-family:"Times New Roman",serif;} 194 p.msolistparagraphcxspmiddle, li.msolistparagraphcxspmiddle, div.msolistparagraphcxspmiddle 195 {mso-style-name:msolistparagraphcxspmiddle; 196 margin-top:0in; 197 margin-right:0in; 198 margin-bottom:0in; 199 margin-left:.5in; 200 margin-bottom:.0001pt; 201 font-size:12.0pt; 202 font-family:"Times New Roman",serif;} 203 p.msolistparagraphcxsplast, li.msolistparagraphcxsplast, div.msolistparagraphcxsplast 204 {mso-style-name:msolistparagraphcxsplast; 205 margin-top:0in; 206 margin-right:0in; 207 margin-bottom:0in; 208 margin-left:.5in; 209 margin-bottom:.0001pt; 210 font-size:12.0pt; 211 font-family:"Times New Roman",serif;} 200 212 span.GSAS-IItextChar 201 213 {mso-style-name:"GSAS-II text Char"; … … 211 223 font-family:"Calibri",sans-serif; 212 224 font-weight:bold;} 225 p.msochpdefault, li.msochpdefault, div.msochpdefault 226 {mso-style-name:msochpdefault; 227 margin-right:0in; 228 margin-left:0in; 229 font-size:10.0pt; 230 font-family:"Calibri",sans-serif;} 213 231 .MsoChpDefault 214 232 {font-size:10.0pt; 215 233 font-family:"Calibri",sans-serif;} 216 /* Page Definitions */ 217 @page WordSection1 234 @page WordSection1 218 235 {size:8.5in 11.0in; 219 236 margin:1.0in 1.0in 1.0in 1.0in;} … … 233 250 <p class=MsoNormal>In this exercise you will use GSAS-II to simulate the 234 251 diffraction patterns from faulted diamond. Diamond most commonly has the 235 well-known cubic structure with the space group Fd3m and a=3.5668A. The C-atom 236 is at 1/8,1/8,1/8 and can be viewed as a cubic stacking of ruffled hexagonal 237 netsalong the cubic cell 111 diagonal. </p>238 239 <p class=MsoNormal><img width=482 height=361 id="Picture 1"252 well-known cubic structure with the space group Fd3m and a=3.5668A. The C-atom is 253 at 1/8,1/8,1/8 and can be viewed as a cubic stacking of ruffled hexagonal nets 254 along the cubic cell 111 diagonal. </p> 255 256 <p class=MsoNormal><img width=482 height=361 240 257 src="Stacking%20Faults-I_files/image001.jpg"></p> 241 258 242 <p class=MsoNormal>The structure of lon sdaleite has those layers stacked259 <p class=MsoNormal>The structure of londsdaleite has those layers stacked 243 260 hexagonally and thus a faulted diamond structure may occasionally have 244 261 hexagonal stacked layers instead of all cubic ones. From geometric … … 248 265 Otherwise, if there are many such faults then the diffraction pattern will show 249 266 streaks. To simulate the streaks one must first develop a model for the 250 hexagonal net of C-atoms and then show how they stack in either the cubic or hexagonal251 forms. GSAS-II uses a suite of subroutines from the DIFFaX program (M.M.J. 252 Treacy, J.M. Newsam & M.W. Deem, (1991), Proc. Roy. Soc. Lond. 433A, 253 4 99-520) to calculate the diffraction pattern via a general recursion algorithm254 a nd a randomized set of stacked layers. NB: this calculation can be quite time255 consuming particularly if unreasonable demands are made on it. </p>267 hexagonal net of C-atoms and then show how they stack in either the cubic or 268 hexagonal forms. GSAS-II uses a suite of subroutines from the DIFFaX program 269 (M.M.J. Treacy, J.M. Newsam & M.W. Deem, (1991), Proc. Roy. Soc. Lond. 270 433A, 499-520) to calculate the diffraction pattern via a general recursion 271 algorithm and a randomized set of stacked layers. NB: this calculation can be 272 quite time consuming particularly if unreasonable demands are made on it. </p> 256 273 257 274 <p class=MsoNormal>If you have not done so already, start GSAS-II.</p> … … 266 283 select it; the data window will display the default for the General tab.</p> 267 284 268 <p class=MsoNormal><img width=620 height=334 id="Picture 2"285 <p class=MsoNormal><img width=620 height=334 269 286 src="Stacking%20Faults-I_files/image002.gif"></p> 270 287 … … 274 291 style='font-family:"Calibri",sans-serif'>diamond</span></b>.</p> 275 292 276 <p class=MsoNormal><img width=624 height=370 id="Picture 3"293 <p class=MsoNormal><img width=624 height=370 277 294 src="Stacking%20Faults-I_files/image003.gif"></p> 278 295 … … 286 303 the window will be redrawn.</p> 287 304 288 <p class=MsoNormal><img width=624 height=464 id="Picture 4"305 <p class=MsoNormal><img width=624 height=464 289 306 src="Stacking%20Faults-I_files/image004.gif"></p> 290 307 291 308 <p class=MsoNormal>The a cell parameter for diamond stacking can be assumed to 292 be a<span style='font-size:12.0pt;font-family:"Times New Roman",serif; 293 position:relative;top:3.0pt'><img width=27 height=21 294 src="Stacking%20Faults-I_files/image005.gif"></span> = <b><span 295 style='font-family:"Calibri",sans-serif'>2.522</span></b> and the c cell 296 parameter is a<span style='font-size:12.0pt;font-family:"Times New Roman",serif; 297 position:relative;top:3.0pt'><img width=27 height=21 298 src="Stacking%20Faults-I_files/image006.gif"></span> = <b><span 299 style='font-family:"Calibri",sans-serif'>2.059</span></b> since there are 3 300 layers along the 111 diamond cell diagonal. Enter these in the appropriate 301 places; the cell volume will be revised.</p> 309 be a<span style='position:relative;top:3pt'><img width=27 height=21 310 src="Stacking%20Faults-I_files/image005.gif"> = <b><span style='font-family: 311 "Calibri",sans-serif'>2.522</span></b> and the c cell parameter is a<span 312 style='position:relative;top:3pt'><img width=27 height=21 313 src="Stacking%20Faults-I_files/image006.gif"> = <b><span style='font-family: 314 "Calibri",sans-serif'>2.059</span></b> since there are 3 layers along the 111 315 diamond cell diagonal. Enter these in the appropriate places; the cell volume 316 will be revised.</p> 302 317 303 318 <p class=MsoNormal>Now we have to describe the two hexagonal nets that will be … … 306 321 will be redrawn.</p> 307 322 308 <p class=MsoNormal><img width=624 height=479 id="Picture 5"323 <p class=MsoNormal><img width=624 height=479 309 324 src="Stacking%20Faults-I_files/image007.gif"></p> 310 325 … … 315 330 and the window will be redrawn with one line in the layer table.</p> 316 331 317 <p class=MsoNormal><img width=624 height=479 id="Picture 6"332 <p class=MsoNormal><img width=624 height=479 318 333 src="Stacking%20Faults-I_files/image008.gif"></p> 319 334 … … 326 341 the window should show the new position.</p> 327 342 328 <p class=MsoNormal><img width=624 height=479 id="Picture 8"343 <p class=MsoNormal><img width=624 height=479 329 344 src="Stacking%20Faults-I_files/image009.gif"></p> 330 345 … … 333 348 will appear. </p> 334 349 335 <p class=MsoNormal><img width=486 height=363 id="Picture 10"350 <p class=MsoNormal><img width=486 height=363 336 351 src="Stacking%20Faults-I_files/image010.jpg"></p> 337 352 … … 344 359 for the layer symmetry. The window should look like this when done.</p> 345 360 346 <p class=MsoNormal><img width=624 height=624 id="Picture 11"361 <p class=MsoNormal><img width=624 height=624 347 362 src="Stacking%20Faults-I_files/image011.gif"></p> 348 363 … … 354 369 reminiscent of how carbon sheets stack in graphite. </p> 355 370 356 <p class=MsoNormal><img width=479 height=358 id="Picture 12"371 <p class=MsoNormal><img width=479 height=358 357 372 src="Stacking%20Faults-I_files/image012.jpg"></p> 358 373 … … 375 390 like.</p> 376 391 377 <p class=MsoNormal><img width=477 height=357 id="Picture 13"392 <p class=MsoNormal><img width=477 height=357 378 393 src="Stacking%20Faults-I_files/image013.jpg"></p> 379 394 … … 384 399 twin fault will be shown.</p> 385 400 386 <p class=MsoNormal><img width=483 height=361 id="Picture 14"401 <p class=MsoNormal><img width=483 height=361 387 402 src="Stacking%20Faults-I_files/image014.jpg"></p> 388 403 389 <p class=MsoNormal>If you enter 1 2 1 2 1 2 1 2 then the structure of 390 lonsdaleite will be shown; 1 1 1 1 1 1 or 2 2 2 2 2 2 gives the diamond 391 structure. </p> 404 <p class=MsoNormal>If you enter 1 2 1 2 1 2 1 2 then the structure of londsdaleite 405 will be shown; 1 1 1 1 1 1 or 2 2 2 2 2 2 gives the diamond structure. </p> 392 406 393 407 <p class=MsoNormal>Finally we must select transition probabilities; they should … … 410 424 options.</p> 411 425 412 <p class=MsoNormal><img width=242 height=136 id="Picture 15"426 <p class=MsoNormal><img width=242 height=136 413 427 src="Stacking%20Faults-I_files/image017.gif"></p> 414 428 … … 420 434 The data window will be redrawn</p> 421 435 422 <p class=MsoNormal><img width=624 height=474 id="Picture 16"436 <p class=MsoNormal><img width=624 height=474 423 437 src="Stacking%20Faults-I_files/image018.gif"></p> 424 438 … … 428 442 (or <b><span style='font-family:"Calibri",sans-serif'>U</span></b>); I got</p> 429 443 430 <p class=MsoNormal><img width=484 height=455 id="Picture 17"444 <p class=MsoNormal><img width=484 height=455 431 445 src="Stacking%20Faults-I_files/image019.gif"></p> 432 446 … … 447 461 some choices.</p> 448 462 449 <p class=MsoNormal><img width=322 height=268 id="Picture 18"463 <p class=MsoNormal><img width=322 height=268 450 464 src="Stacking%20Faults-I_files/image020.gif"></p> 451 465 … … 453 467 lab data</span></b>; a new popup will appear</p> 454 468 455 <p class=MsoNormal><img width=318 height=342 id="Picture 19"469 <p class=MsoNormal><img width=318 height=342 456 470 src="Stacking%20Faults-I_files/image021.gif"></p> 457 471 … … 490 504 interesting stuff around each peak.</p> 491 505 492 <p class=MsoNormal><img width=624 height=587 id="Picture 20"506 <p class=MsoNormal><img width=624 height=587 493 507 src="Stacking%20Faults-I_files/image022.gif"></p> 494 508 … … 504 518 <p class=MsoNormal>A perhaps useful means of exploring the effects of changing 505 519 stacking parameters is doing a sequence of simulations varying one parameter 506 over a range. To try this out do Operations/Sequence simulations from the507 Layers menu; a popup will appear</p>508 509 <p class=MsoNormal><img width=279 height=191 id="Picture 21"520 over a range. To try this out do <b><span style='font-family:"Calibri",sans-serif'>Operations/Sequence 521 simulations</span></b> from the Layers menu; a popup will appear</p> 522 523 <p class=MsoNormal><img width=279 height=191 510 524 src="Stacking%20Faults-I_files/image023.gif"></p> 511 525 … … 514 528 parameter</span></b> pulldown choose <b><span style='font-family:"Calibri",sans-serif'>TransP;0;0</span></b>; 515 529 this is the layer 1 to layer 1 transition probability. Then change the no. 516 steps to <b><span style='font-family:"Calibri",sans-serif'>10</span></b> (11 517 will be calculated). We have the same choices for instrument broadening as 518 above;use the default. Press <b><span style='font-family:"Calibri",sans-serif'>Ok</span></b>;530 steps to <b><span style='font-family:"Calibri",sans-serif'>10</span></b> (11 will 531 be calculated). We have the same choices for instrument broadening as above; 532 use the default. Press <b><span style='font-family:"Calibri",sans-serif'>Ok</span></b>; 519 533 the next popup allows selection of a powder pattern (e.g. for comparison and 520 534 the range for the calculation). Press <b><span style='font-family:"Calibri",sans-serif'>Ok</span></b> … … 530 544 result?</span></b> box; a new plot will appear.</p> 531 545 532 <p class=MsoNormal><img width=624 height=535 id="Picture 22"546 <p class=MsoNormal><img width=624 height=535 533 547 src="Stacking%20Faults-I_files/image024.gif"></p> 534 548 … … 538 552 Ive done this for the next plot.</p> 539 553 540 <p class=MsoNormal><img width=624 height=535 id="Picture 23"554 <p class=MsoNormal><img width=624 height=535 541 555 src="Stacking%20Faults-I_files/image025.gif"></p> 542 556 543 <p class=MsoNormal>The first blue line is for pure hexagonal lon sdaleite544 stacking and the last magenta line is for pure cubic diamond stacking. You can see 545 how some lines quickly vanish with the introduction of stacking faults while 546 other persist across the entire sequence. This is a good place to save your 547 projectfile; the sequential result will be included.</p>557 <p class=MsoNormal>The first blue line is for pure hexagonal londsdaleite stacking 558 and the last magenta line is for pure cubic diamond stacking. You can see how 559 some lines quickly vanish with the introduction of stacking faults while other 560 persist across the entire sequence. This is a good place to save your project 561 file; the sequential result will be included.</p> 548 562 549 563 <h2>Simulation 4. Modelling clustering in diamond</h2> … … 551 565 <p class=MsoNormal>In this simulation we will explore the possibility that the 552 566 stacking history affects the probability of a fault. In the case of diamond, a 553 fault to form lon sdaleite could be followed by similar layers until a lower567 fault to form londsdaleite could be followed by similar layers until a lower 554 568 probability fault converts the structure back to diamond. The crystal then has 555 blocks of diamond structure interleaved with blocks of lon sdaleite. This is569 blocks of diamond structure interleaved with blocks of londsdaleite. This is 556 570 best done in a new phase so we dont mess up the above simulations, but most of 557 571 the data in the current phase is useful for the cluster model. The easiest way … … 567 581 General tab for the new phase will appear.</p> 568 582 569 <p class=MsoNormal><img width=624 height=336 id="Picture 24"583 <p class=MsoNormal><img width=624 height=336 570 584 src="Stacking%20Faults-I_files/image026.gif"></p> 571 585 … … 573 587 of the tabs; select it.</p> 574 588 575 <p class=MsoNormal><img width=624 height=474 id="Picture 26"589 <p class=MsoNormal><img width=624 height=474 576 590 src="Stacking%20Faults-I_files/image027.gif"></p> 577 591 … … 594 608 <p class=MsoNormal> </p> 595 609 596 <p class=MsoNormal><img width=624 height=474 id="Picture 28"610 <p class=MsoNormal><img width=624 height=474 597 611 src="Stacking%20Faults-I_files/image028.gif"></p> 598 612 … … 609 623 <p class=MsoNormal> </p> 610 624 611 <table class=Mso TableGrid border=1cellspacing=0 cellpadding=0612 style='border-collapse:collapse ;border:none'>625 <table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 626 style='border-collapse:collapse'> 613 627 <tr style='height:21.45pt'> 614 628 <td width=72 valign=top style='width:54.05pt;border:solid windowtext 1.0pt; … … 748 762 Transition tables should look like</p> 749 763 750 <p class=MsoNormal><img width=624 height=620 id="Picture 29"764 <p class=MsoNormal><img width=624 height=620 751 765 src="Stacking%20Faults-I_files/image029.gif"></p> 752 766 … … 762 776 will look like</p> 763 777 764 <p class=MsoNormal><img width=624 height=535 id="Picture 30"778 <p class=MsoNormal><img width=624 height=535 765 779 src="Stacking%20Faults-I_files/image030.gif"></p> 766 780
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