NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system
| ISSN: |
0022-3697
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|---|---|
| Source: |
Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
|
| Topics: |
Chemistry and Pharmacology
Physics
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| Type of Medium: |
Electronic Resource
|
| URL: |
| _version_ | 1798292522052616193 |
|---|---|
| autor | Korn, C. Zamir, D. |
| autorsonst | Korn, C. Zamir, D. |
| book_url | http://linkinghub.elsevier.com/retrieve/pii/0022-3697(70)90089-2 |
| datenlieferant | nat_lic_papers |
| fussnote | The proton spin lattice relaxation time T"1 has been measured by an NMR pulse technique at 19.00 MHz as a function of temperature in the range 25^o-500^oC for a series of samples in the α, β and γ phases of titanium hydride. The relaxation mechanism in the α and γ phases was governed primarily by hydrogen diffusion over most of the temperature range. The diffusional activation energy in the γ phase was found to be constant with respect to the hydrogen concentration, having a value of 11.77 +/- 0.4 kcalmole, and the attempt jump frequency was found to be proportional to the available local vacancies. The activation energy behavior is discussed in relation to a previously proposed model for hydrogen diffusion in titanium and the jump attempt frequency is compared to available data on the optical mode of the hydrogen vibrations. Evidence was found for a uniform distribution in the γ phase when the ratio of hydrogen to titanium, x, is greater than 1.6 while clustering takes place at lower ratios. The low temperature γ phase transition concentration at x = 1.6 was found to be related to the electronic structure from (T"1)"e data. The conduction electrons were the primary cause of relaxation in the γ phase near room temperature and the contribution of this mechanism to the relaxation rate increased with increase in hydrogen concentration. (T"1)"eT ranged from 190 +/- 4sec-^oK to 62.5 +/- 2 sec -^oK as x (the ratio of hydrogen to titanium atoms) varied from 1.55 to 1.90. The α + gg, γ phase boundary was found between 25^o and 100^oC. Diffusion parameters were measured for the α phase and the gradual transition from the α + γ to γ region observed. The transition from the α + γ to the β phase was observed and a heating-cooling hysteresis effect was displayed. T"1, for the β phase near 450^oC of TiH"0"."7"8 was governed mainly by the conduction electrons and a value of(T"1)"eT = 58+/-5 sec -^oK was found. |
| hauptsatz | hsatz_simple |
| identnr | NLZ178644463 |
| issn | 0022-3697 |
| journal_name | Journal of Physics and Chemistry of Solids |
| materialart | 1 |
| package_name | Elsevier |
| publikationsort | Amsterdam |
| publisher | Elsevier |
| reference | 31 (1970), S. 489-502 |
| search_space | articles |
| shingle_author_1 | Korn, C. Zamir, D. |
| shingle_author_2 | Korn, C. Zamir, D. |
| shingle_author_3 | Korn, C. Zamir, D. |
| shingle_author_4 | Korn, C. Zamir, D. |
| shingle_catch_all_1 | Korn, C. Zamir, D. NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system 0022-3697 00223697 Elsevier |
| shingle_catch_all_2 | Korn, C. Zamir, D. NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system 0022-3697 00223697 Elsevier |
| shingle_catch_all_3 | Korn, C. Zamir, D. NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system 0022-3697 00223697 Elsevier |
| shingle_catch_all_4 | Korn, C. Zamir, D. NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system 0022-3697 00223697 Elsevier |
| shingle_title_1 | NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system |
| shingle_title_2 | NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system |
| shingle_title_3 | NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system |
| shingle_title_4 | NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system |
| sigel_instance_filter | dkfz geomar wilbert ipn albert fhp |
| source_archive | Elsevier Journal Backfiles on ScienceDirect 1907 - 2002 |
| timestamp | 2024-05-06T08:49:51.248Z |
| titel | NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system |
| titel_suche | NMR study of hydrogen diffusion in the three different phases of the titanium-hydrogen system The proton spin lattice relaxation time T"1 has been measured by an NMR pulse technique at 19.00 MHz as a function of temperature in the range 25^o-500^oC for a series of samples in the α, β and γ phases of titanium hydride. The relaxation mechanism in the α and γ phases was governed primarily by hydrogen diffusion over most of the temperature range. The diffusional activation energy in the γ phase was found to be constant with respect to the hydrogen concentration, having a value of 11.77 +/- 0.4 kcalmole, and the attempt jump frequency was found to be proportional to the available local vacancies. The activation energy behavior is discussed in relation to a previously proposed model for hydrogen diffusion in titanium and the jump attempt frequency is compared to available data on the optical mode of the hydrogen vibrations. Evidence was found for a uniform distribution in the γ phase when the ratio of hydrogen to titanium, x, is greater than 1.6 while clustering takes place at lower ratios. The low temperature γ phase transition concentration at x = 1.6 was found to be related to the electronic structure from (T"1)"e data. The conduction electrons were the primary cause of relaxation in the γ phase near room temperature and the contribution of this mechanism to the relaxation rate increased with increase in hydrogen concentration. (T"1)"eT ranged from 190 +/- 4sec-^oK to 62.5 +/- 2 sec -^oK as x (the ratio of hydrogen to titanium atoms) varied from 1.55 to 1.90. The α + gg, γ phase boundary was found between 25^o and 100^oC. Diffusion parameters were measured for the α phase and the gradual transition from the α + γ to γ region observed. The transition from the α + γ to the β phase was observed and a heating-cooling hysteresis effect was displayed. T"1, for the β phase near 450^oC of TiH"0"."7"8 was governed mainly by the conduction electrons and a value of(T"1)"eT = 58+/-5 sec -^oK was found. |
| topic | V U |
| uid | nat_lic_papers_NLZ178644463 |