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X-ray diffraction patterns demonstrated a significant nanocrystalline body-centred cubic CoFe (110) structure when the thickness was between 60 and 90 nm, and displayed an amorphous status when the...

To investigate the correlations between different thicknesses and heat treatments, this study used a sputtering method to create CoFeY films. The results of X-ray diffraction (XRD) revealed the appearance of oxide peaks at 2θ = 47.7°, 54.5°, and 56.3° in agreement with YFeO3 (212), Co2O3 (422), and Co2O3 (511), respectively. The findings also demonstrated a relationship between the low-frequency alternative-current magnetic susceptibility (χac) values and the thickness of the CoFeY thin films. At a thickness of 50 nm and an annealing temperature of 300 °C, the ideal value of ac was 0.159. The presence of Y and the thickness impact were both evident in the χac value, which improved spin-exchange coupling as well as grain refining. With increasing thickness, the resistance decreased. At 300 °C and 40 nm in thickness, this film has a maximum surface energy of 31.2 mJ/mm2. The hardness of the 50-nm films reached a maximum of 16.67 GPa when annealed at 100 °C. Due to the high χac, strong adhesion, good nanomechanical properties, and low resistivity, the optimal conditions were determined to be 50 nm with annealing at 300 °C.

Yuan-tsung Chen writes her memoir in the midst of growing unrest when in 2019 the Communist rulers try to pass an extradition law in Hong Kong’s Legislative Council. To begin with, they set about “reforming” middle schoolers’ education— for instance, through the Orwellian rewriting of the history of the Cultural Revolution, from the ten-year-long “cataclysm” (Hao Jie—浩劫‎) to the ten years of “arduous exploration and development achievement.” Even according to the official death toll, 1.7 million people perished in the Cultural Revolution. The dead had families or relatives, friends or lovers, so how many more lives were ruined? Yuan-tsung simply cannot accept such a whitewashing without a guilty conscience. She is fully aware of the consequences of confronting the untruth. Nevertheless, she decides to write what she witnessed, saw, and understood as truth.

After Khrushchev’s denunciation of Stalin, Mao announced his so-called liberalizing movement, the Hundred Flowers Campaign, which was really a trap to get opponents and doubters of his magnificence to expose themselves. Before she was aware of the purpose of the campaign, Yuan-tsung took her manuscript out of the drawer in which it was hidden and looked forward to the glorious moment of its publication in what she thought would be a new, freer atmosphere. She planned to go back to Shanghai. She split with Jack. But just before publication, Mao savagely cracked down on his critics. During the Anti-Rightist Purge, she burned her own manuscript.

The Red Guards, backed by the Maoist military representatives stationed in Jack’s office, cajoled Yuan-tsung and Jack into going to the backwater Upper Felicity Village, which was the Red Guards’ final solution to the problem of disposing of the couple. But Yuan-tsung reconnected with Jack’s American brother-in-law, Jay Leyda, who was teaching at York University in Canada. Eventually, with the secret help of a fellow victim Yuan-tsung had met by happenstance on a bus, and despite some letters intercepted by Red Guards, Jack was able to get messages from Leyda. Leyda succeeded in organizing a speech tour for Jack to Canadian and American universities, and informed Zhou Enlai of it. On the prime minister’s personal order, Jack was brought back to Beijing and granted exit visas for the family. After the tour of Chinese cities arranged by Zhou Enlai, Jack, Yuan-tsung, and their son left China in May 1971, two months before Kissinger’s secret visit to China in July.

The Anti-Rightist Campaign continued, claiming more than half a million victims, and it was a close call for Yuan-tsung. She witnessed the fall of her immediate boss, Director Wang, at his heartbreaking last meeting with his little daughter, Oriole. She also witnessed the fall of Zeng Zhaolun and the destruction of the Democratic League, the influential “third-way” party of which Zeng was a founding member. Zeng’s wife Yu Dayin, Yuan-tsung’s best friend, was a collateral victim. It broke both her heart and her spirit to see her husband being taken away. The tragedies happening around Yuan-tsung made her think she would not be spared, but at this juncture she reunited with her ex-lover, Jack, who came back from a trip on the Silk Road.

Yuan-tsung reunited with Phyllis Wu at her salon in Chongqing and started to learn social skills by helping her entertain guests. In this way, Yuan-tsung came into close social contact with some of the country’s leading politicians and intellectuals, getting to know them not so much in their official capacities as in more informal settings, when they relaxed over tea or wine. Among them was Zhou Enlai, then the Communist representative to China’s “United Front,” the tense, shaky arrangement whereby the Communists and the Nationalists supposedly worked together to defeat the Japanese invaders. At parties and dinners she heard them talk about the role of the Third Force, and “Vinegar Joe” Stilwell, and watched as Zhou Enlai cultivated these US-educated intellectuals so as to gain access to influential Americans.

Zhou Enlai tried but failed to protect Jack, and so in 1969, Jack and Yuan-tsung were evicted from their apartment and forced to live in a corner room at a slum house on Sheep Market Street. Most of their neighbors came from the urban underclass; among them were a retired prostitute, a semireformed thief, a laundress who doubled as a bed playmate to her employer, and an old witch who practiced black magic. They were purveyors of gossip and became new sources of information for Yuan-tsung. A Japanese woman named Noriko, punching bag to her Chinese husband, became Yuan-tsung’s best friend and played a key role in her fight against the Red Guards.

Yuan-tsung awaited her fate, sure that it would be the same as that of her immediate boss, Director Wang, who had been driven to suicide, but Jack came to her rescue. They reconciled and got married in 1958. She lived a privileged life in his “magic circle,” which, up to that time, was untouched by either purges or famines. But in that magic circle, she watched with terror and apathy as the disastrous Great Leap Forward and the ensuing Great Famine unfolded. Feeling it morally wrong that she did not suffer with the others, she volunteered in 1960, the worst famine year, to go to a famine-devastated rural area, the Red Flag People’s Commune. To survive, she had to hunt for food like the other villagers.

The Second World War ended in victory for the Nationalist government. It was a Pyrrhic victory, however, as the Nationalists would soon be defeated by the Communists in the civil war, and Yuan-tsung was at a crossroads, wondering what to do: join her rich friends and flee to Hong Kong or stay in China. Despite her mother’s insistence that she go south with her rich friends, she decided with her younger siblings’ support to stay, believing that earthshaking events were about to happen in China and that they would provide material for her literary endeavors. She decided to go north to Beijing and meanwhile began to read some radical literature, such as Gorky’s Mother.

From the time she was a girl, Yuan-tsung Chen had had a literary dream, and in 1950 she embarked on a literary career, a journey filled with thrilling and dangerous adventures. She went to Beijing and got a job in the Scenario Department of the Central Film Bureau, where she found herself in a front-row seat during China’s culture wars as Mao Zedong demanded that literature and art serve the Party, while writers wanted culture to be distinguishable from propaganda. Hence she became a secret listener. Purges ensued. She narrowly escaped the Anti-Rightist Purge of 1957 by marrying Jack Chen, who, because of his connections, had avoided political trouble so far. Mao’s “class war” continued. His Great Leap Forward caused the plunge in agricultural production and the greatest famine of the twentieth century. It led to Mao’s last and most violent purge, the Cultural Revolution. His hitmen, the Red Guards, viciously attacked Jack. Yuan-tsung went secretly to ask Zhou Enlai, the prime minister, for help. Zhou tried but failed to protect them. They were sent out of Beijing and consigned to a rural backwater village, cut off from all recourse to friends. But Yuan-tsung figured out a way to get in touch, right under the noses of the Red Guards, with Jack’s American brother-in-law and asked him to arrange a speaking tour for Jack. He did, and thus Jack was able to accept an invitation to lecture on Canadian and American campuses. After a tense wait, on the prime minister’s personal order Jack and Yuan-tsung got permits to leave the country.

Yuan-tsung blended further into village life, getting to know more villagers and their survival kit. One of them, a woman cadre named Winter Plum, initiated her into the black market, where she could get better food from a drunken butcher. Old Xu, the ever so complaisant village head, surprised her with his bitter resentment against his higher-ups and his bitterness over the loss of his family’s cohesion caused by collectivization. Wimpy Gu, the reticent and meek assistant to Old Xu, relieved himself occasionally with violent, emotional outbursts. Old Hong, renowned locally as the gloriously demobilized soldier, or Glorious Demob, amazed her with his web of deceit and lies for the sake of manufacturing a fake bumper harvest.

In 1966, the Cultural Revolution broke out. Chen Yi, the foreign minister and Zhou Enlai’s right-hand man, sent a message to Jack, through Comrade Xia on a secret errand, that he would grant Jack an exit visa if he applied for one. But soon Mao’s Red Guards ran amok. Chen Yi was pushed aside. Jack, no longer protected by his family’s reputation and his own connections, was assaulted and not allowed to leave the compound of the Foreign Languages Bureau, where he worked on the English edition of the Peking Review. Yuan-tsung, however, was mobile. She went to see the Red Guards rally at Tiananmen; each of the participants held the Little Red Book, the compilation of Mao’s quotes.

In early 1941 , Yuan-tsung’s family moved to Chongqing, the wartime capital of the Nationalist government, where she attended the prestigious Nankai Middle School and went through the trials and discoveries of adolescence, though shadowed by war and byzantine domestic politics. This was also the time of her romantic and sexual awakening, though it took place in a vicarious manner. She accompanied her wealthy best friend, Edith Shen, to the latter’s tryst at the Peach-Blossom Grove. She acted as an intermediary for Edith, the school beauty queen, and her lover, a role that earned her a place in one of Chongqing’s most elegant mansions.

Yuan-tsung reunited with two friends from her Chongqing days, Yu Dayin and her husband, Zeng Zhaolun, who took her to a meeting of the Political Consultative Conference, where she witnessed Mao’s withering attack on Liang Shumin, a Confucian scholar, who criticized Mao’s agricultural policy. This was followed by Mao’s purge of Hu Feng, a maverick literary critic, who had criticized Mao’s dictates on culture and had written a manifesto challenging them. The two incidents led Yuan-tsung to come to some painful political realizations—among them that writing under Mao’s reign was a life-and-death matter.

In addition to working in the fields, Yuan-tsung helped in the office of Red Flag Village’s Party secretary, Old Xu, who eventually took her into his confidence. He let her in on an almost comical attempt to smuggle a fat pig past starving peasants, so that the Party bigwigs could feast on it. It opened her eyes to the corruption and shenanigans of village politics, which mirrored the state of affairs nationwide. Meanwhile it brought her close to the victims and she became their friend. One of them, Lotus Boy, talented and gentle, would soon die of starvation and political persecution.

Yuan-tsung, meaning “First Pearl,” was born to a middle-class family in Shanghai, the Paris of the East, not rich, but well connected, and since childhood her ambitious mother had groomed her to climb the social ladder. Her father, though loving, was somewhat ineffectual. He lost his job in a scandal, and the family began to come down in the world. Because she was the eldest of three siblings, she felt obligated to reverse the family fortune. Her maiden performance as a social climber, when she met and attracted the attention of a powerful socialite, Phyllis Wu, during a grand party at the Fairy Glen Hotel, made her mother think she had great potential.

In May 1971, the Chens arrived in Hong Kong. In October of the same year, Jack went on his speaking tour. It was a success, and they decided to emigrate to the United States. Both worked at Cornell University, and then in 1978, they moved to the San Francisco Bay Area, where Yuan-tsung worked at the East Asiatic Library at the University of California, Berkeley until she retired in 1992. In 2010, she moved to Hong Kong and started to write her present memoir. After the Party authorities implemented the National Security Law in 2020, the strategy of “shock and awe” put Yuan-tsung on tenterhooks. However, in spite of herself, she was determined to complete her book and get it published.

In 1967, during a mutiny known as the Wuhan Incident, Zhou Enlai flexed his political muscles and pacified the insurgent commanders. Mao felt threatened. Yuan-tsung’s friend Courtier Yu, her direct link to Zhou, warned her that she had been caught in the crossfire of a huge power struggle between Zhou and Mao. Zhou wanted to reach an understanding with the West that would lead to the lifting of its trade sanctions against China. Mao, however, wanted to resuscitate the Great Leap Forward. Yuan-tsung’s best bet was Zhou. If Zhou prevailed, he would use Jack’s knowledge of English and Western culture to explain his open-door policy to the West. In return Jack and Yuan-tsung would get their exit visas. Courtier Yu arranged a meeting at a place near Badaling where Yuan-tsung could take her plea directly to Zhou.

To advance her career, Yuan-tsung was obliged to demonstrate her loyalty to the Party by doing whatever it wanted her to do, and so in late 1950, she went to do land reform work in a poverty-stricken farming village, known as Dragon’s Village, outside the Great Wall in northwestern Gansu Province. Six months later, she returned to Beijing, and at a weekend party, an old Nankai schoolmate, Dora Zhang, introduced her to Jack Chen, an overseas Chinese who, along with his father, had been an early supporter of the Communists. At the party, they waltzed to the music of the “Blue Danube.” She was not as impressed by Chen’s political pedigree as by his library, which included banned works by writers like Marcel Proust and D. H. Lawrence. They talked about these “decadent writers” and fell in love.

With the Japanese invasion of China in 1937, Yuan-tsung’s family moved to an inland city, Kunming, capital of Yunnan Province, or more precisely, to a backwater called Little Stone Village, where she accidentally met Double-Minister Sa, her father’s boss, and had her first affair. Though Yuan-tsung was only twelve, Sa fell for her, though not in any perverse or overtly erotic way; something about her made him want to talk, to reveal his private thoughts and struggles. His attention, inappropriate as it might have been, boosted her confidence about breaking into the social circle of her mother’s dreams.

Yuan-tsung returned to Beijing in November 1960, but she could not forget what she had seen in the Red Flag Commune, and so she planned to circumvent another, probably worse catastrophe. She discussed options with Jack. Both agreed to leave China for Hong Kong, where Jack’s brother Percy ran the Marco Polo Club, a sort of bridge between Western businessmen and China. Jack would work as a freelance journalist. They consulted their friend Comrade Xia. Xia arranged for Jack to meet the foreign minister, Chen Yi, who liked to wear a French Beret. Chen Yi thought it was a good idea that Jack continue his work in a less restrictive environment. But Yuan-tsung and Jack disagreed on when to depart. She preferred 1965 and he, 1966. She was afraid that anything might happen in that one year.

This study investigated Co40Fe40W20 single-layer thin films according to their corresponding structure, grain size, contact angle, and surface energy characteristics. Co40Fe40W20 alloy thin films of different thicknesses, ranging from 10 to 50 nm, were sputtered on Si(100) substrates by DC magnetron sputtering. The thin films were annealed under three conditions: as-deposited, 250 °C, and 350 °C temperatures, respectively. The Scherrer equation was applied to calculate the grain size of Co40Fe40W20 thin films. The results show that the grain size of CoFe(110) increased simultaneously with the increase of post-annealing temperature, suggesting that the crystallinity of Co40Fe40W20 thin films increased with the post-annealing temperature. Moreover, the contact angles of all Co40Fe40W20 thin films were all less than 90°, suggesting that Co40Fe40W20 thin films show changes in the direction of higher hydrophilicity. However, we found that their contact angles decreased as the grain size of CoFe increased. Finally, the Young equation was applied to calculate the surface energy of Co40Fe40W20 thin films. After post-annealing, the surface energy of Co40Fe40W20 thin films increased with the rising post-annealing temperature. This is the highest value of surface energy observed for 350 °C. In addition, the surface energy increased as the contact angle of Co40Fe40W20 thin films decreased. The high surface energy means stronger adhesion, allowing the formation of multilayer thin films with magnetic tunneling junctions (MTJs). The sheet resistance of the as-deposited and thinner CoFeW films is larger than annealed and thicker CoFeW films. When the thickness is from 10 nm to 50 nm, the hardness and Young’s modulus of the CoFeW film also show a saturation trend.

In this study, X-ray diffraction (XRD) analysis showed the amorphous nature of the Co60Fe20Yb20 films deposited at room temperature (RT), 100 °C, and 200 °C. The body-centered cubic (BCC) CoFe (110) characteristic peak was visible at 44.7° after annealing films of 40 nm and 50 nm at 300 °C. The highest alternating current magnetic susceptibility (χac) value was 0.21 at 50 Hz in a 50 nm, and the lowest resistivity value was 1.02 (×10−2 Ω·cm) in a 50 nm. In terms of nano-indication measurement, the highest value of hardness was 9.29 GPa at 300 °C in a 50 nm. When the thickness increased from 10 nm to 50 nm, the hardness and Young’s modulus of the Co60Fe20Yb20 film also showed a saturation trend. The Co60Fe20Yb20 film had the maximum surface energy at 50 nm after 300 °C annealing. The transmittance of Co60Fe20Yb20 films decreased when the thickness was increased because the thickness effect suppresses the photon signal. Due to high χac, low electrical performance, strong nano-mechanical properties, and high adhesion, it was discovered in this work that 50 nm with annealing at 300 °C was the ideal condition for the magnetic and adhesive capabilities of Co60Fe20Yb20 film. More importantly, replacing the CoFeB seed or buffer layer with a thin CoFeYb film improved the thermal stability, making CoFeYb films attractive for practical magnetic tunnel junction (MTJ) applications. Furthermore, the specific properties of Co60Fe20Yb20 films were compared to those of Co60Fe20Y20 films, demonstrating that the specific properties of these two materials may be compared.

Co40Fe40W20 monolayers of different thicknesses were deposited on Si(100) substrates by DC magnetron sputtering, with Co40Fe40W20 thicknesses from 10 to 50 nm. Co40Fe40W20 thin films were annealed at three conditions (as-deposited, 250 °C, and 350 °C) for 1 h. The structural and magnetic properties were then examined by X-ray diffraction (XRD), low-frequency alternative-current magnetic susceptibility (χac), and an alternating-gradient magnetometer (AGM). The XRD results showed that the CoFe (110) peak was located at 2θ = 44.6°, but the metal oxide peaks appeared at 2θ = 38.3, 47.6, 54.5, and 56.3°, corresponding to Fe2O3 (320), WO3 (002), Co2O3 (422), and Co2O3 (511), respectively. The saturation magnetization (Ms) was calculated from the slope of the magnetization (M) versus the CoFeW thickness. The Ms values calculated in this manner were 648, 876, 874, and 801 emu/cm3 at the as-deposited condition and post-annealing conditions at 250, 350, and 400 °C, respectively. The maximum MS was about 874 emu/cm3 at a thickness of 50 nm following annealing at 350 °C. It indicated that the MS and the χac values rose as the CoFeW thin films’ thickness increased. Owing to the thermal disturbance, the MS and χac values of CoFeW thin films after annealing at 350 °C were comparatively higher than at other annealing temperatures. More importantly, the Co40Fe40W20 films exhibited a good thermal stability. Therefore, replacing the magnetic layer with a CoFeW film improves thermal stability and is beneficial for electrode and strain gauge applications.

This study investigated the structure and magnetic properties of Co40Fe40V20 thin films with a thicknesses (tf) of 10 nm to 100 nm on a glass substrate. The X-ray diffraction (XRD) patterns of the CoFeV films demonstrated a significant crystalline body-centered cubic (BCC) CoFe (110) structure when the thickness was between 60 and 100 nm, and an amorphous status were shown when the thickness was from 10 to 50 nm. The strongest crystalline XRD peak was at 60 nm because it had a continuous mode of film growth and induced a large grain distribution. The low-frequency alternating current magnetic susceptibility (ϰac) property decreased when the frequency increased. The lowest ϰac value was detected at 60 nm owing to the large grain distribution inducing high coercivity (Hc) and then enhancing the spin coupling strength. The external field (Hext) was difficult to rotate spin state, then deduces the spin sensitivity and ϰac value is decreased. The highest ϰac meant the spin sensitivity was maximized at the optimal resonance frequency. The 50-mm thickness had the highest ϰac 0.045 value at an fres of 100 Hz. The fres value was less than 1000 Hz at all CoFeV thicknesses, suggesting that CoFeV films would be suitable for low-frequency magnetic component applications. Moreover, the saturation magnetization (Ms) revealed a thickness effect when the thicknesses had a larger Ms. The Hc values were between 3 Oe and 10 Oe at all CoFeV films, except for 60 nm. The Hc of the 60 nm film was about 80 Oe due to the larger grain distribution, and it induced strong remanent magnetization (Mr) and a larger squareness ratio (Mr/Ms) of 92%. The results of the magnetic measurement showed that the 60 nm Co40Fe40V20 film had greater Hc and a good squareness ratio.

The low-frequency alternating current magnetic susceptibility (χac) property decreased when the frequency increased. The highest χac meant the spin sensitivity was maximized at an fres. Of ...

The structure, magnetic properties, optical properties and adhesion efficiency of CoFeBY films were studied. Co40Fe40B10Y10 alloy was sputtered onto Si (100) with a thickness of 10–50 nm, and then annealed at room temperature, 100 °C, 200 °C and 300 °C for 1 h. X‑ray diffraction (XRD) showed that the CoFeBY films deposited at room temperature are amorphous. Annealing at 100 °C gave the films enough thermal energy to change the structure from amorphous to crystalline. After annealing, the CoFeBY thin film showed a body-centered cubic (BCC) CoFeB (110) characteristic peak at 44°. However, the low‑frequency alternative‑current magnetic susceptibility (χac) and saturation magnetization (MS) increased with the increase of thickness. CoFeBY thin films had the highest χac and MS after annealing at 300 °C compared to that at other temperatures. After annealing at 300 °C, the surface energy of CoFeBY film is the maximum at 50 nm. Higher surface energy indicated stronger adhesion.

In this study, a 10&ndash, 50 nm Co32Fe30W38 alloy thin film sputtered on glass substrates was annealed at different temperatures for 1 h including room temperature (RT), 300, 350, and 400 &deg, C. The structure, magnetic properties, surface energy, and optical properties of the Co32Fe30W38 alloy were studied. X-ray diffraction (XRD) patterns of the as-deposited Co32Fe30W38 thin films showed the amorphous structure. The apparent body-centered cubic (BCC) CoFe (110) structure was exhibited after 300 &deg, C annealing for 1 h. The 300 &deg, C annealed Co32Fe30W38 thin film showed the highest CoFe (110) peak compared with other temperatures. Furthermore, the thicker the Co32Fe30W38 thin film, the higher the CoFe (110) peak. The CoFe (110) peak revealed magneto-crystalline anisotropy, which was related to the strong low-frequency alternative-current magnetic susceptibility (&chi, ac) and induced an increasing trend of saturation magnetization (Ms) as the thickness (tf) increased. Due to the thermal disturbance, the &chi, ac and Ms for the 350 and 400 &deg, C annealed Co32Fe30W38 thin film decreased. The contact angles of the Co32Fe30W38 thin films were less than 90&deg, For all temperatures, the surface energy increased when the film thickness increased from 10 to 50 nm. In addition, the surface energies for annealed samples were comparatively higher than the as-deposited samples. The higher surface energy of 28 mJ/mm2 was obtained for the 50 nm Co32Fe30W38 thin film annealed at 300 &deg, C. The transmittance percentage (%) of the as-deposited Co32Fe30W38 film was higher than other annealed conditions. This result contributed to the fact that higher crystallization, due to perfect band structures, may inhibit the transmission of photon signals through the film, resulting in low transmittance and high absorption.

In this study, a Co40Fe40W20 alloy was sputtered onto Si (100) with thicknesses (tf) ranging from 18 to 90 nm, and the corresponding structure, magnetic properties, adhesive characteristics, and nanomechanical properties were investigated. X-ray diffraction (XRD) patterns of the Co40Fe40W20 films demonstrated a significant crystalline body-centered cubic (BCC) CoFe (110) structure when the thickness was 42 nm, and an amorphous status was shown when the thickness was 18 nm, 30 nm, 60 nm, and 90 nm. The saturation magnetization (Ms) showed a saturated trend as tf was increased. Moreover, the coercivity (Hc) showed a minimum 1.65 Oe with 30 nm. Hc was smaller than 4.5 Oe owing to the small grain size distribution and amorphous structure, indicating that the Co40Fe40W20 film had soft magnetism. The low-frequency alternating current magnetic susceptibility (χac) decreased as the frequency was increased. The χac revealed a thickness effect when greater thicknesses had a large χac. The maximum χac and optimal resonance frequency (fres) of Co40Fe40W20 were investigated. The maximum χac indicated the spin sensitivity and was maximized at the optimal resonance frequency. The 90 mm thickness had the highest χac 0.18 value at an fres of 50 Hz. The contact angles of the Co40Fe40W20 films are less than 90°, which indicated that the film had a good wetting effect and hydrophilicity. The surface energy was correlated with the adhesion and displayed a concave-down trend. CoFeW films can be used as a seed or buffer layer; therefore, the surface energy and adhesion are very important. The highest surface energy was 30.12 mJ/mm2 at 42 nm and demonstrated high adhesion. High surface energy has corresponding strong adhesive performance. The increased surface roughness can induce domain wall pinning effect and high surface energy, causing a high coercivity and strong adhesion. The increase of hardness and Young’s modulus could be reasonably inferred from the thinner CoFeW films. The hardness and Young’s modulus of CoFeW films are also displayed to saturated tendency when increasing thickness.

When B and V are added to CoFe material, the mechanical strength and spin tunneling polarization of a CoFe alloy can be improved and enhanced by the high tunneling magnetoresistance (TMR) ratio. Based on these reasons, it is worthwhile investigating Co40Fe40V10B10 films. In this work, X-ray diffraction (XRD) showed that Co40Fe40V10B10 thin films have some distinct phases including CoFe (110), CoFe (200), FeB (130), and V (110) diffracted peaks with the strongest diffracted peak for 30 nm. The lowest low-frequency alternate-current magnetic susceptibility (&chi, ac) was detected at 30 nm because the large grain distribution inducing that high coercivity (Hc) enhances the spin coupling strength and low &chi, ac. The external field (Hext) had difficulty rotating in the spin state, hence, the spin sensitivity was reduced and the &chi, ac value decreased due to increased surface roughness. The 20 mm thickness had the highest &chi, ac 1.96 &times, 10&minus, 2 value at 50 Hz of an optimal resonance frequency (fres). The surface energy increased from 34.2 mJ/mm2 to 51.5 mJ/mm2 for Co40Fe40V10B10 films. High surface energy had corresponding strong adhesive performance. According to the magnetic and surface energy results, the optimal thickness is 20 nm due as it had the highest &chi, ac and strong adhesion.