A Combined TEM/STEM and Micromagnetic Study of the Anisotropic Nature of Grain Boundaries and Coercivity in Nd-Fe-B Magnets

<div>Simulated hysteresis curves of the 27-G-GBj model structure with a distribution of the misorientation angle <svg height="12.5794pt" id="M151" style="vertical-align:-3.29107pt" version="1.1" viewbox="-0.0498162 -9.28833 11.4791 12.5794" width="11.4791pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M501 444C501 643 409 712 321 712C208 712 108 618 108 502C108 412 172 331 293 331C337 331 394 359 420 378C397 154 341 41 258 41C209 41 178 76 178 161C178 232 171 299 114 299C76 299 38 272 23 257L29 232C42 236 54 239 66 239C91 239 106 221 102 149C95 20 158 -12 219 -12C264 -12 314 10 353 47C461 150 501 295 501 444ZM423 443C423 433 422 422 421 412C401 396 370 385 335 385C245 385 180 444 180 537C180 609 212 671 286 671C349 671 423 595 423 443Z" id="g113-248"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="518" vert-adv-y="518"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,6.409,3.132)"><path d="M245 635C92 635 37 457 37 312C37 149 91 -12 244 -12C395 -12 449 166 449 312C449 469 395 635 245 635ZM243 598C332 598 358 454 358 312C358 173 334 26 245 26C158 26 128 174 128 313S152 598 243 598Z" id="g50-49"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="487" vert-adv-y="487"></glyph.data></g></svg> of the hard magnetic grains with an average of 9° and 28°, respectively. The simulation with the greater misorientation has a higher <svg height="13.1967pt" id="M152" style="vertical-align:-4.560801pt" version="1.1" viewbox="-0.0498162 -8.6359 18.4562 13.1967" width="18.4562pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M828 650H570L564 622C646 614 650 609 634 524L604 366H253L281 524C296 608 308 615 382 622L388 650H132L126 622C211 615 214 609 198 524L121 122C106 42 102 35 23 28L17 0H276L282 28C196 35 191 40 206 122L243 324H597L559 123C544 42 537 35 452 28L446 0H710L716 28C632 35 628 43 643 122L719 524C735 610 741 615 822 622L828 650Z" id="g113-73"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="840" vert-adv-y="840"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,10.075,3.132)"><path d="M387 400C387 425 348 451 303 451C247 451 176 414 132 376C69 322 24 228 24 148C24 43 74 -12 147 -12C211 -12 301 33 363 103L346 128C319 99 249 51 193 51C148 51 112 84 112 165C112 230 130 287 154 330C170 359 199 400 243 400C277 400 304 383 326 354C333 345 343 343 354 348C378 360 387 382 387 400Z" id="g50-100"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="411" vert-adv-y="411"></glyph.data></g><g transform="matrix(.0091,0,0,-0.0091,13.654,3.132)"><path d="M434 650H168L162 618C248 609 258 608 243 528L174 155C163 93 153 39 138 1C110 -68 67 -98 24 -111L37 -147C55 -144 75 -136 94 -128C185 -87 232 -12 259 139L328 528C342 605 349 609 427 618L434 650Z" id="g50-75"></path><glyph.data ascent="3443" descent="-2856" horiz-adv-x="458" vert-adv-y="458"></glyph.data></g></svg> (by 5%).</div>

Advances in Materials Science and Engineering

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Figure 12

Figure 12: A Combined TEM/STEM and Micromagnetic Study of the Anisotropic Nature of Grain Boundaries and Coercivity in Nd-Fe-B Magnets 