3. Results and discussionFig. 1(a)

3. Results and discussion
Fig. 1(a) shows the x-ray diffraction spectra of the as-deposited
films and annealed films at various Ta (450e800
C). Note that intensity
axis for each pattern is plotted on a logarithmic scale and
shifted for clarity. For the as-deposited FePt film, it exhibited a
disordered fcc structure with (111) texture. After an annealing at
Ta ¼ 500
C, a very weak (001) diffraction peak was found, indicating
an emergence of L10 phase. The intensities of (001) and (002)
reflections enhanced as increasing RTA temperature, which were
even stronger than that of (111) reflection in the samples with
Ta  600
C. This evidences a crystallographic orientation alteration
from (111) to (001) plane. To further investigate the dependence of
Ta on evolution of preferred orientation, a semi-quantitative
parameter, Lotgering orientation factor (LOF) was adopted [18]. In
case of (001) preferred orientation in FePt, LOF is defined as
LOF ¼ (pp0)/(1p0), where p and p0 refer to S(00l)film/S(hkl)film
and S(00l)powder/S(hkl)powder, respectively. Accordingly, LOF ranges
from a certain negative value to 1. The negative value represents a
preferred orientation other than (001), 0 means a random orientated
state, and 1 refers to a prefect (001) texture. Dependence of
LOF on Ta is shown in Fig. 1(b). For the as-deposited film and
annealed film at 450
C, LOF values were 0.138, indicating a (111)
preferred orientation. With increasing Ta from 450 to 700
C, the
LOF value altered from negative value to unity, evidencing a significant
improvement of the (111) preferred orientation. The integrated
intensity ratio of the superlattice (001) and fundamental
(002) peaks was used to determine the ordering parameter of L10
phase (S) according to Warren's theory [19]. As illustrated in Fig. 1
(c), S value increased from 0 to greater than 0.9 as Ta was raised
from 450 to 600
C. No significant variation of S with increasing Ta
further was observed. It is worthy to note that the onset temperature
(500
C) for development of S and (001) texture was likely to
be the same; however, the progress of Swas more rapid than that of
(001) orientation. This result suggests that the L10 phase transformation
is one of key factors for (001) texture formation [11],
especially for determination of the onset annealing condition.
Furthermore, we also noticed that interference fringes in thevicinity of the Bragg peaks for the sample annealed at Ta ¼ 700 and
800
C, indicating the high coherence of lattice and surface flatness.
Out-of-plane and in-planeM-H loops of the rapid-annealed FePt
films at various temperatures are presented in Fig. 2. For the sample
annealed at 500
C (Fig. 2 (a)), a longitudinal magnetic anisotropy
with out-of-plane coercivity (Hc) of 2.5 kOe was found owing to a
LOF value of 0.138. Although the LOF dramatically enhances
from 0.138 to 0.88 with increasing Ta from 450 to 650
C
(Fig. 2(b)e(c)), the magnetic anisotropy barely evolves from longitudinal
to isotropic state. A significant evolution of magnetic
anisotropy from isotropic to perpendicular behavior was observed
as annealing temperature was raised up to 700
C (Fig. 2(d)). The
FePt film annealed at 700
C shows excellent PMA with out-ofplane
Hc of 9.1 kOe and in-plane Hc of 1.6 kOe. The in-plane MH
loop exhibits a slight hysteresis at low applied field owing to the caxis
distribution in the perpendicular direction. For the highest Ta of
800
C, an excellent PMA with out-of-plane Hc of 10.0 kOe and inplane
Hc of 0.1 kOe was achieved. The (001) textured L10-FePt film
with Ts ¼ 800
C exhibited a high perpendicular magnetic

ผลลัพธ์ (ไทย) 1:

3. Results and discussionFig. 1(a) shows the x-ray diffraction spectra of the as-depositedfilms and annealed films at various Ta (450e800
C). Note that intensityaxis for each pattern is plotted on a logarithmic scale andshifted for clarity. For the as-deposited FePt film, it exhibited adisordered fcc structure with (111) texture. After an annealing atTa ¼ 500
C, a very weak (001) diffraction peak was found, indicatingan emergence of L10 phase. The intensities of (001) and (002)reflections enhanced as increasing RTA temperature, which wereeven stronger than that of (111) reflection in the samples withTa  600
C. This evidences a crystallographic orientation alterationfrom (111) to (001) plane. To further investigate the dependence ofTa on evolution of preferred orientation, a semi-quantitativeparameter, Lotgering orientation factor (LOF) was adopted [18]. Incase of (001) preferred orientation in FePt, LOF is defined asLOF ¼ (pp0)/(1p0), where p and p0 refer to S(00l)film/S(hkl)filmand S(00l)powder/S(hkl)powder, respectively. Accordingly, LOF rangesfrom a certain negative value to 1. The negative value represents apreferred orientation other than (001), 0 means a random orientatedstate, and 1 refers to a prefect (001) texture. Dependence ofLOF on Ta is shown in Fig. 1(b). For the as-deposited film andannealed film at 450
C, LOF values were 0.138, indicating a (111)preferred orientation. With increasing Ta from 450 to 700
C, theLOF value altered from negative value to unity, evidencing a significantimprovement of the (111) preferred orientation. The integratedintensity ratio of the superlattice (001) and fundamental(002) peaks was used to determine the ordering parameter of L10phase (S) according to Warren's theory [19]. As illustrated in Fig. 1(c), S value increased from 0 to greater than 0.9 as Ta was raisedfrom 450 to 600
C. No significant variation of S with increasing Tafurther was observed. It is worthy to note that the onset temperature(500
C) for development of S and (001) texture was likely tobe the same; however, the progress of Swas more rapid than that of(001) orientation. This result suggests that the L10 phase transformationis one of key factors for (001) texture formation [11],especially for determination of the onset annealing condition.Furthermore, we also noticed that interference fringes in thevicinity of the Bragg peaks for the sample annealed at Ta ¼ 700 and800
C, indicating the high coherence of lattice and surface flatness.Out-of-plane and in-planeM-H loops of the rapid-annealed FePtfilms at various temperatures are presented in Fig. 2. For the sampleannealed at 500
C (Fig. 2 (a)), a longitudinal magnetic anisotropywith out-of-plane coercivity (Hc) of 2.5 kOe was found owing to aLOF value of 0.138. Although the LOF dramatically enhancesfrom 0.138 to 0.88 with increasing Ta from 450 to 650
C(รูป 2(b)e(c)) ดาวเทียมสำรวจคลื่นแม่เหล็กแทบไม่ปรากฏขึ้นตามยาวการรัฐ isotropic วิวัฒนาการสำคัญของแม่เหล็กดาวเทียมสำรวจคลื่นจาก isotropic ลักษณะตั้งฉากการถูกตรวจสอบเป็นการหลอมอุณหภูมิขึ้นสูงถึง 700 C (รูป 2(d)) การฟิล์ม FePt อบที่ 700 C แสดงสารประกอบเยี่ยมกับ ofplane ออกHc kOe 9.1 และ Hc ในระนาบของ 1.6 kOe MH ในเครื่องบินวนรอบแสดงสัมผัสเล็กน้อยที่ต่ำใช้ฟิลด์เนื่องจากการ caxisกระจายในทิศตั้งฉาก สำหรับตาสูงสุดของ800 C สารประกอบยอดเยี่ยมกับ Hc ออกบิน 10.0 kOe และ inplaneHc ของ 0.1 kOe สำเร็จ (001) พื้นผิวฟิล์ม L10-FePtมี Ts ¼ 800 C กุมารตั้งฉากสูงที่แม่เหล็ก