摘要:

Resonance field position and amplitude for two possible ferromagnetic resonances varied greatly with alignment of the applied magnetic field (Hdc) in the range 2°–10° from the a‐axis in the hexagonal plane of the sample (T=77–140 K); these resonances are not easily explained by present theories. The higher field peak is not as well defined and is an order of magnitude broader in linewidth than the lower field peak. When Hdcwas aligned 1°–2° from the a‐axis in the hexagonal plane, the resonances followed closely the free lattice model predictions of Vigren and Liu for Hdcexactly along the a‐axis. The resonances forT=77–140 Kwere only observable when Hdcwas not precisely aligned along an a‐axis in the hexagonal plane.

ISSN:0094-243X    

DOI:10.1063/1.2953892

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The coercive force of Dy single crystals has been measured at low temperatures using both D. C. and A. C. methods to verify the predicted intrinsic coercive force. The coercive force was found to depend upon the field sweep rate, increasing monotonically with sweep rate, but reaching a maximum (intrinsic) value above a certain sweep rate. The observed intrinsic coercive force is in a good agreement with theory, both in magnitude and in temperature dependence.

ISSN:0094-243X    

DOI:10.1063/1.2953893

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The Tcof Gd, when subjected to hydrostatic pressures, decreases by about 1°C/kbar. It is to be expected then that film stresses of the order of kbars should also change the Tcof Gd. High purity polycrystalline films of Gd were deposited onto oxidized silicon and sapphire wafers by rf sputtering. By varying the substrate temperatures during deposition, it was possible to vary the film stress from −6.5 kbar (compressive) to +1 kbar (tensile). The variation in Tcwas linear with a slope of 1.8°C/kbar which is in good agreement with the value reported above for bulk Gd of about 1°C/kbar.

ISSN:0094-243X    

DOI:10.1063/1.2953894

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The temperature dependence of the electrical resistivity and the magnetic susceptibility has been investigated for the compoundsUAl2,UAl3and the isostructural compoundsUX3(X=Ga, In, Si, Ge, Sn), and finally forUAl4andUGa2. The influence of a variable U concentration has been studied for the pseudobinary compoundsU1−xYxAl2andU1−xYxGa2. The results are discussed in terms of a localized‐spin‐fluctuations model. The differences and the similarities between the electrical properties of these U compounds and Ce compounds, such asCeAl2andCeAl3, are briefly discussed.

ISSN:0094-243X    

DOI:10.1063/1.2953895

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The susceptibility ofTmTeincreases continuously between 18 and 29 kbar at room temperature, while at helium temperature it increases between 29 and 39 kbar and flattens out above, indicating the existence of three separate electronic phases. The increase of the magnetization is unhysteretic and smaller than expected for a full transformation from Tm2+to Tm3+at all temperatures and pressures. The low temperature magnetization curves in the high pressure phases are very non‐linear.

ISSN:0094-243X    

DOI:10.1063/1.2953896

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The magnetization of all cubic intermetallic compounds of the formPuX2andPuX3, where X is a nonmagnetic GroupVIIItransition metal, have been measured between 2.5°–300°K.PuRh2,PuPt2,PuRh3,PuPd3, andPuPt3have effective paramagnetic moments of about 1 &mgr;Bper formula unit. The latter three compounds order magnetically withTN = 6.2°K, 24°K, and 59°K, respectively.PuPt2has a spontaneous moment belowTC = 6°Kof about 0.2 &mgr;B.PuPt2is probably an itinerant ferromagnet, while localized magnetic moments are apparently well formed inPuPt3. The degree of localization of electrons in the other magnetic compounds is probably intermediate to that found in these two cases.

ISSN:0094-243X    

DOI:10.1063/1.2953897

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The magnetic anisotropies, defined as the difference in magnetic susceptibility perpendicular to the c‐axis and parallel to the c‐axis, &khgr;⊥c‐&khgr;∥c, of hcp scandium, dilute scandium‐base alloys with both magnetic and nonmagnetic solutes, and high purity technetium have been studied as a function of temperature between 2 and 300°K. The magnetic anisotropy of scandium is not affected by small amounts of nonmagnetic impurities such as cerium and thorium. The anisotropy changes drastically at low temperature when scandium is alloyed with the magnetic solutes gadolinium and dysprosium. The magnetic anisotropy &khgr;⊥c‐&khgr;∥cchanges sign from positive to negative at low temperature in theSc‐Gd alloys. The sign of &khgr;⊥c‐&khgr;∥cremains positive but increases by several orders of magnitude with decreasing temperature in theSc‐Gd alloys.

ISSN:0094-243X    

DOI:10.1063/1.2953898

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The impurity contribution to the spin‐lattice relaxation of the Al27nuclei has been studied in the compoundsLa0.99Ce0.01Al2andLa0.95Tm0.05Al2. The impurity component of the magnetization recovery is observed to be non‐exponential, which is attributed to diffusionless relaxation of the nuclei to the magnetic impurities. An analysis of the functional dependence of the resulting rate, 1/&tgr;1, indicates that longitudinal fluctuations of the dipolar field are the principal relaxation mechanism. An analysis in the RKKY approximation indicates the strength of the impurity‐conduction electron coupling in the Ce and Tm cases respectively is 2.5 and 1.7 times that forLaAl2Gd.

ISSN:0094-243X    

DOI:10.1063/1.2953899

出版商:AIP    

年代:1972

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.2953900

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Recent measurements of magnetic losses in a 3% Si‐Fe single crystal sheet ((100) [001] orientation) with a slab‐like domain structure have shown that the losses measured in the two ⟨100⟩ directions in the plane of the sheet are quite different. Using the Kerr magneto‐optical effect and high‐speed photography, the dynamic domain structures were observed. In the “hard” direction of magnetization, (magnetization in a ⟨100⟩ direction normal to the static domain walls) 90 degree domain walls are nucleated and annihilated each half cycle. The magnetic losses for magnetization in this direction were calculated by using a domain model for losses and considering the movement of 90 and 180 degree walls. A relationship between the losses in the hard direction and the “easy” direction (magnetization in a ⟨100⟩ direction parallel to the static domain walls) is found and is consistent with the previous experimental data.

ISSN:0094-243X    

DOI:10.1063/1.2953901

出版商:AIP    

年代:1972

数据来源: AIP